TSB
screen printing => Separations => Topic started by: AdvancedArtist on April 12, 2013, 04:07:19 PM
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This is a breakdown of HSB into simple terms that I hope will assist you in your understand of HSB, color and color separations for screen printing.
HSB and Screen Printing (http://www.youtube.com/watch?v=BCkuZPFyCKk#ws)
More to come..
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See now that was a great post. The video was awesome and informative and very interesting. The whole HSB is difficult to grasp for me anyways initially, it's confusing when you say black is your lightness and saturation is your white. Watching another video from you is starting to make sense with those terms.
I applaud the fact that you are basically showing how your software works but I know as well as you should know only some will take the knowledge to do their own manual seps. In general most will purchase your software to automate the process. You have to admit there is a whole lot of clicking and clicking to do before you even get to the int of ripping. It makes sense to offer a macro plug in to make it much quicker, so even teaching people how to do the process manually many if not most will still want the macro you offer.
I your opinion that crayon image you are using in total how many colors would you have that stepped as to keep it as close to the original as possible, and what would you guess what the color count be if it was stepped traditionally as a sim process or index?
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Hi inkman thanks for the post.. Because of all the color I think you would have all the colors..
Red
Yellow
Green
Cyan
Blue
and Megenta
And of course black and possibly whites depending the on the garment color.
Or if you wanted more vibrancy you would sep colors like the orange, brown and purples and pulls of those color respectively.
For me getting to the hue with the easy black removal was just a game changer. BAM your looking at the color and then you can make analysis about what you would want to do with the separation.
After a while you start to get HSB eyes were you can look at things and see what is going on with the color.
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Thanks AA for that excellent video. I learned enough about color in that 12+ minute span to make me a bit more dangerous with my inks!
Simple Seps Raster also makes more sense to me now as well.
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Thanks AA for that excellent video. I learned enough about color in that 12+ minute span to make me a bit more dangerous with my inks!
Simple Seps Raster also makes more sense to me now as well.
Thanks Sparkie based on your post mission accomplished 8)
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For your reading pleasure HWB almost made it.... but I guess it did not get all the way there.
http://alvyray.com/Papers/CG/HWB_JGTv208.pdf (http://alvyray.com/Papers/CG/HWB_JGTv208.pdf)
But giving that a read is worth the time for sure. The science behind the simplicity.
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I agree with mike nice post, in fact this the AA i met when i first bought DRAW in `09
teaching the garage squeegee printers like myself how to use the software towards screen printing that said.
when someone in the industry comes up with a new method of doing things that`s healthy, makes the industry rolling
competition is a good thing keep us sharp on the edge of things
whether you sep in this software or that software manually or plug in, push or pull the squeegee
there`s nothing wrong with that
get it done teammates ;)
Gabe
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Ugh, does this mean I need to buy/learn Corel Draw? :(
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Ugh, does this mean I need to buy/learn Corel Draw? :(
No. You can still do this in photoshop.
AA is automating the process for Corell Draw though. And Customers are reporting it works well!
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Ugh, does this mean I need to buy/learn Corel Draw? :(
No. You can still do this in photoshop.
AA is automating the process for Corell Draw though. And Customers are reporting it works well!
I'd like to try, but so far, I can't even get Corel loaded onto my pc in the office. Windows Update is apparently missing (in the services list, thanks Mike for getting me there) so I still can't install Corel, which wants to install Frameworks 4.0 (I think that's right) because of no Windows Update. What a friggin' pain. Back to the subject at hand, nice post Tom, thank you.
Steve
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:-X
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Hey Scott, you're on theshirtboard!! That's what's up..
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:-X
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P.S. -- Been lurking for a while, people been posting my vids and all... Did you think I was gonna let Tom have all the fun?? :D
Just keep your "fun" civil and friendly. ;) One Tom is plenty (some would say too much as it is)
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Hi Jeff... I've found your videos (and Tom's) very interesting. Good stuff.
More info, more learning, this is good.
Positivity.
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Its nice to know this is coming out to more than just a few. I know a guy that has sepped for over 20 years and he has been using HSB for a long time. His seps have been killing it for a long time.
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I sepped a design today that wouldn't come out right in PS at all with both Easy Art and Quikseps, SS Raster nailed it. I didn't print any of them yet, but closest to the original goes to SS raster. And it did it in fewer colors.
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Here is perfect example of why you need to understand this it can be game changer in your business especially when you have limited press colors.
Below is client supplied art needing 6 color in spot colors. The printer only has a 4 color press. Going with the typical spot color route the printer would not have enough colors. However converting the vector to raster and then sepping from the HSB understand it can be done with just 3 colors or 4 if going on black tshirts. Especially if the guy down street quotes 6 colors and you quote 3. Also you will be able to get the most color you can out of your limited press colors.
Now we can see that HSB opens up much more than just separation but an easier understanding of color to work with and the ability to get colors down on some jobs easily.
(http://advancedtshirts.com/hsbmulticolor.jpg)
This is critical and everyone needs to understand color clearly. That is what we do as printers reproduce images and graphics in color HSB makes it easy and accurate.
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Not busting your chops Tom but I fail to see your vodoo with your technique on the above example. I look at it and see three colors easily, I would never think that had to be done in six nor five as a rule. I know if it was vector I could rip it myself but if provided to me as a raster someone like Dan or many others here could give that back to me as three on whites.
Obviously the image would print better with more colors such as the maroonish color, it simply would look better as a spot color versus a mix which BTW is not always the easiest thing for print shops to accomplish. Everyone under the sun has different printing parameters than the next guy, inks are different, mesh counts are all over the board and obviously not all shops can nail perfect halftones required to pull off decent color blending on press.
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Not busting your chops Tom but I fail to see your vodoo with your technique on the above example. I look at it and see three colors easily, I would never think that had to be done in six nor five as a rule. I know if it was vector I could rip it myself but if provided to me as a raster someone like Dan or many others here could give that back to me as three on whites.
Obviously the image would print better with more colors such as the maroonish color, it simply would look better as a spot color versus a mix which BTW is not always the easiest thing for print shops to accomplish. Everyone under the sun has different printing parameters than the next guy, inks are different, mesh counts are all over the board and obviously not all shops can nail perfect halftones required to pull off decent color blending on press.
Its not really voodo but a allot of newbies or start ups would look at it that way believe me. We that have experience of course or I could do it as an over print from vector also. But HSB lets us peal back the black and get to the color behind the black in a few easy steps and then HSL sep and it is done. So the process of getting to the color to see what your options are is very simple and the process of sepping can also be very simple.
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Tom, can you post what EasyArt or Quikseps would have spit out on that same design?
I think this is where SS Raster shines is head to head against pre-packaged sep programs.
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Tom, can you post what EasyArt or Quikseps would have spit out on that same design?
I think this is where SS Raster shines is head to head against pre-packaged sep programs.
I would love to but I do not have either of those programs and that one is really simple I just did it manually actually. Channel mixer pulled the black and hue and then with the HSL tool pull the red and yellow out. The part I like most about HSB is the pull back of the black in the correct color space. BAM you see the colors and you also see there densities at which point you can make decisions about how the separation will proceed. For years in PS I was just trying color ranges and other things not pulling my black and sepping from the hue. Which is why it was something I just decided to send out because it was too time consuming and it was to easy to make mistakes. In HSB first step Split Color and Black and the graphic is opened right up then you know what the colors are just pull them.
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After watching your videos I get lost because when you use the hue/saturation/lightness adjustment to pull a color you are only offered red/yellow/cyan/blue/magenta to work with. How do you handle any other color like a purple or some other secondary color?
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I'm sorry I meant the channel mixer
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To pull say a purple you can use the master channel in the HSL to move your purple into say pure Magenta or Blue and then just pull the Magenta or Blue with the HSL or you could shift that color to yellow or megenta and then pull it with the Channel Mixer. If you have Megenta or Blue in the art pull it to a sep before you move your purple to one of the easy to pull colors. I will try to do a vdeo on this within the week its pretty easy or maybe Jeff can do one on this.
There are actually many ways to do this. But it is best to get the black/color split first.
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Tom, can you post what EasyArt or Quikseps would have spit out on that same design?
I think this is where SS Raster shines is head to head against pre-packaged sep programs.
Brad,
Tom was asked behind the scenes to keep his discussion to his products. We value his knowledge and contribution so please let's keep it the way he is doing it right now. Tom, thank you for your contributions and sharing your knowledge. Even though it was said already, it will not hurt to hear it again, it is very much appreciated!!!
thanx,
pierre
p.s. If somebody else with the programs wishes to show the differences, please coordinate with Tom and post. There are no issues with the end users expressing their unbiased opinions. We just want to prevent one manufacturer/supplier/designer or what ever bashing another.
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Tom, can you post what EasyArt or Quikseps would have spit out on that same design?
I think this is where SS Raster shines is head to head against pre-packaged sep programs.
I can see te value in comparing, but I do not want X Co. posting the comparison. I'd rather have a 3rd party such as a MK162 posing the comparison than a representative from any one of those company's. This is the reason I've never posted a comparison of my own seps up against a Quick Seps, T-Seps, EasyArt or a NetSeps. It's not real cool to do and leaves the window open for the question, Did or could that Co stack the deck in their favor so to speak. I'm not saying that any one of those Co's or Tom would or has done this before, but just having a 3rd party posing the comparisons is more like fair play.
So if you own 2-4 of these sep programs and also own Toms Simple Seps raster yourself, feel free to post up te same jobs that has been done by all of them...but better yet, post up a picture...of the same printer....same print parameters...printing the same job. A photo of the printed tees. Thats very telling as well.
I'm sure Toms can turn out very good on press as well as it does on the screen, but like some say, each printer is going to produce a different look than another printer.
I tried this while at Disney before. I separated a job and sent the seps out to 4 different company's and had each print it for approval. Same colors, same everything called out. Each looked different and a few to a great degree....Maybe one looked great and two looked ok but maybe the last looked less perfect than the other three. So, each were pretty sellable and very approvable...yet all slightly different. It was more of a test to show the higher ups that we can get more consistency from shop to shop by providing our own "initial approved seps".
We had first hand knowledge that you could send an art file out to each one...and each separate it how they felt it should be...and the results can be vastly different with 2-5 revisions per every time we took it to a new shop. Wasted time and money.
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Tom, can you post what EasyArt or Quikseps would have spit out on that same design?
I think this is where SS Raster shines is head to head against pre-packaged sep programs.
Brad,
Tom was asked behind the scenes to keep his discussion to his products. We value his knowledge and contribution so please let's keep it the way he is doing it right now. Tom, thank you for your contributions and sharing your knowledge. Even though it was said already, it will not hurt to hear it again, it is very much appreciated!!!
thanx,
pierre
p.s. If somebody else with the programs wishes to show the differences, please coordinate with Tom and post. There are no issues with the end users expressing their unbiased opinions. We just want to prevent one manufacturer/supplier/designer or what ever bashing another.
Ditto.
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Honestly I am more interested in getting the color information out and understanding in HSB as it relates to screen printing more then anything else. Automation is great but understanding the math and reasons with color is the critical point IMHO.
Many here including myself going back year or more would never have imagined I would be presenting this information in CorelDRAW. But it is working with the correct color space, correct color model and the easy tools.
Getting started with Simulated Color Management off a color space that is not destructive and ideal tools for the HSB separating. PS has the same tools and this can be done in PS it just a bit more complicated.
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Brad,
Tom was asked behind the scenes to keep his discussion to his products. We value his knowledge and contribution so please let's keep it the way he is doing it right now. Tom, thank you for your contributions and sharing your knowledge. Even though it was said already, it will not hurt to hear it again, it is very much appreciated!!!
thanx,
pierre
p.s. If somebody else with the programs wishes to show the differences, please coordinate with Tom and post. There are no issues with the end users expressing their unbiased opinions. We just want to prevent one manufacturer/supplier/designer or what ever bashing another.
Pierre,
Would you be open to some critiques relating to the resent award winning prints you had at ISS which were great prints but on the color seps side there is room for improvement. Not in the spirit of competition but in the spirit of understanding and sharing with the goal of improving what is possible in screen printing.
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Brad,
Tom was asked behind the scenes to keep his discussion to his products. We value his knowledge and contribution so please let's keep it the way he is doing it right now. Tom, thank you for your contributions and sharing your knowledge. Even though it was said already, it will not hurt to hear it again, it is very much appreciated!!!
thanx,
pierre
p.s. If somebody else with the programs wishes to show the differences, please coordinate with Tom and post. There are no issues with the end users expressing their unbiased opinions. We just want to prevent one manufacturer/supplier/designer or what ever bashing another.
Pierre,
Would you be open to some critiques relating to the resent award winning prints you had at ISS which were great prints but on the color seps side there is room for improvement. Not in the spirit of competition but in the spirit of understanding and sharing with the goal of improving what is possible in screen printing.
ALWAYS!!! (For any that have not corresponded with me, my email signature for almost 20 years now is "On a perpetual quest for knowledge. . .")
I have been watching your and Jeff's videos for a while and an opportunity to learn more would be fantastic. And no, yo are not going to hurt my feelings, I know there is room for improvement in those prints as I have seen, much, much better.
Lot of the HSB stuff being brought up was already explained to me by Mark Coudray, but I have spent last few days going over the videos and writing scripts for Photoshop. While Mark's info was purely theoretical, having an opportunity to learn how to do it and actually see the results has been extremely valuable. As you mentioned, seeing the color without the black is eye opening! The first time I did it it was one of those moments you remember for the rest of your life.
All said an done though, I am not completely sold on doing the seps that way. From what I have seen (and some of those were done by MC himself), there seems to be too much black and white ink going on that's muddying the results. At this point, my thinking is that using darker pigments will create nicer color than using a lighter pigment and reducing the brightness with black (for example, pure pigment PMS187 (if it existed) should look nicer than a 185 with some black in it). This could all be related to my lack of knowledge when it comes to ink ingredients and some very limited understanding of the color theory. Now, I might be thinking in terms outside the practical or even theoretical realm, so I would (always) welcome any opportunity to learn/see something new.
I am also pretty certain, based on my experience (and from both provided and self separated art) that using HSB for the white generation is not the absolute best way to go despite what some well respected industry superstars are thinking. There are issues in the 20-50 degree range that HSB handles rather poorly (when it comes to white generation), but that is a discussion in it self and I went off on a tangent here, sorry.
PM me directly and we'll work something out. I am even willing to print your seps to see how they come out and honestly present the results or do any other testing/help that would help improve the processes currently in use by the industry and/or ourselves.
pierre
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Brad,
Tom was asked behind the scenes to keep his discussion to his products. We value his knowledge and contribution so please let's keep it the way he is doing it right now. Tom, thank you for your contributions and sharing your knowledge. Even though it was said already, it will not hurt to hear it again, it is very much appreciated!!!
thanx,
pierre
p.s. If somebody else with the programs wishes to show the differences, please coordinate with Tom and post. There are no issues with the end users expressing their unbiased opinions. We just want to prevent one manufacturer/supplier/designer or what ever bashing another.
Pierre,
Would you be open to some critiques relating to the resent award winning prints you had at ISS which were great prints but on the color seps side there is room for improvement. Not in the spirit of competition but in the spirit of understanding and sharing with the goal of improving what is possible in screen printing.
ALWAYS!!! (For any that have not corresponded with me, my email signature for almost 20 years now is "On a perpetual quest for knowledge. . .")
I have been watching your and Jeff's videos for a while and an opportunity to learn more would be fantastic. And no, yo are not going to hurt my feelings, I know there is room for improvement in those prints as I have seen, much, much better.
Lot of the HSB stuff being brought up was already explained to me by Mark Coudray, but I have spent last few days going over the videos and writing scripts for Photoshop. While Mark's info was purely theoretical, having an opportunity to learn how to do it and actually see the results has been extremely valuable. As you mentioned, seeing the color without the black is eye opening! The first time I did it it was one of those moments you remember for the rest of your life.
All said an done though, I am not completely sold on doing the seps that way. From what I have seen (and some of those were done by MC himself), there seems to be too much black and white ink going on that's muddying the results. At this point, my thinking is that using darker pigments will create nicer color than using a lighter pigment and reducing the brightness with black (for example, pure pigment PMS187 (if it existed) should look nicer than a 185 with some black in it). This could all be related to my lack of knowledge when it comes to ink ingredients and some very limited understanding of the color theory. Now, I might be thinking in terms outside the practical or even theoretical realm, so I would (always) welcome any opportunity to learn/see something new.
I am also pretty certain, based on my experience (and from both provided and self separated art) that using HSB for the white generation is not the absolute best way to go despite what some well respected industry superstars are thinking. There are issues in the 20-50 degree range that HSB handles rather poorly (when it comes to white generation), but that is a discussion in it self and I went off on a tangent here, sorry.
PM me directly and we'll work something out. I am even willing to print your seps to see how they come out and honestly present the results or do any other testing/help that would help improve the processes currently in use by the industry and/or ourselves.
pierre
I cannot thank you enough for that post lets get to bottom this I will contact you soon! 8)
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I would be willing to take an image and see what it spits out from each program.
The question is should we tweak the image before the sep and not after? I think it would be best to use the same exact image to see how close it gets.
I will have to dig up quickseps(which I am not sure if it's even sold anymore, I think it's now ultraseps...maybe somebody can do this one for me).
I think this would be a great comparison, strictly for education and product showcasing. And it might be one of those things where some programs do great with some images and terrible with others.
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What you get at final (before tweaks) is the raw product. The product each SimpleSepsHSB customer will get. Those unique and individual adjustments that each printer will do make all the difference. How much more work you add into those seps or need to do, all reflect on the outcome that is based on the ability of the user.
For example, The guy down the street may use Xprogram and print what he gets from it with (his) adjustments) if any needed but he's not that experienced with inks and color (no matter what program he uses). Another guy up the street can be a more seasoned person knowing how to separate already...and uses that same Xprogram for some added efficiency and can come out with a far better result. Both used Xpromgram.
One looks great to him but is far from an award winner yet he's astonished and his customer loves it.
The other more seasoned guy is satisfied but knows it's not an award winner...and he gets the job out the door a little faster than had he done it all himself. This makes any program beneficial that helps things move along faster and/or better while making the customer happy.
In addition to these programs, the quality of the seps are all based on not just the sep plug in/action quality or process used to get to that point, but also based on the printers experience/ability to print it.
A sep program or action script or color model, or a professional separator (no matter how great either are) is not a magic pill for your answer to all issues that will make each of us print better.
In order for Pierre to have a true comparison using SimpleSepsHBS against (my own separations), Pierre would have to do the SimpleSepsHSB labor of the seps himself....Not a Tom Knight and not a Jeff, so that we can compare SimpleSepsHSB in it's raw form...with the skills of an average user. He can take the SimpleSepsHSB sep file and print it on a few shirts...and then compare that to what he has won an award with, take photo's and post the printed images of the shirts in detail.
If Brad (Mk162) does this comparison as well, it's the same scenario. He should sep a file that he uses on each program using (his skills) for tweaking.
This, I would be game for. Using a 3rd party to do the comparison and not the skills of the maker of the program (no matter what program).
1st, the art being used needs to be approved by the owner of the art before being included.
I addition, I think it's best that (THE FORUM members) be the judge of the images and be the only ones able to comment on a newly created section however temporary or permanent that may be. Not the people doing the submissions and not the people owning the programs and not the person who did the manual separations.
As an assurance that those involved do not participate, have the ability here to disable or enable specific members to post in a specific or a newly created category so that could be a +
No matter the results, I am interested to see as well. If I am as Tom says, put out of the separations business, so be it. I have other things to fall back on, but even if this took off like gang busters as they feel it will, I doubt it will totally replace the need for outside sources or other sep programs. Business as usual. Just another option added to the mix is my guess but I wish the all the best in their business with it.
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There is no doubt that touch up and tweaking on the arbitrary side has its place as I have often said screen printing is art on garments. Color adjustments for pop and vivid printing will always be a part of the game. I have no desire to put anyone out of business. I would just like see all us of with our eyes and minds open to color. For so long this has been a sort of mysterious side of this business if we take some of mystery out of it and make it understandable and approachable then we have succeeded.
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There is no doubt that touch up and tweaking on the arbitrary side has its place as I have often said screen printing is art on garments. Color adjustments for pop and vivid printing will always be a part of the game. I have no desire to put anyone out of business. I would just like see all us of with our eyes and minds open to color. For so long this has been a sort of mysterious side of this business if we take some of mystery out of it and make it understandable and approachable then we have succeeded.
Agreed.
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I addition, I think it's best that (THE FORUM members) be the judge of the images and be the only ones able to comment on a newly created section however temporary or permanent that may be. Not the people doing the submissions and not the people owning the programs and not the person who did the manual separations.
As I have said in my posts I am not trying to push SimpleSeps Raster I am trying to open up color and understanding relating to color. Making analysis of the before and after with or without the perfect result can help us to identify ways to make analysis in the pre separation and post separation phase.
Should I have pulled tints, shades, primary and or secondary colors or a custom color? I have 360 degrees of Colors/Hues which I can pull or manipulate in any way I want.
All of which is revealed when the black is pulled back. This is the key step in the decision making process.
So analyzing the results in my opinion could be very beneficial. Not from a which product is better or worse but from looking at color, the analysis of it and separation of it.
Just my 2 cents..
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I addition, I think it's best that (THE FORUM members) be the judge of the images and be the only ones able to comment on a newly created section however temporary or permanent that may be. Not the people doing the submissions and not the people owning the programs and not the person who did the manual separations.
As I have said in my posts I am not trying to push SimpleSeps Raster I am trying to open up color and understanding relating to color. Making analysis of the before and after with or without the perfect result can help us to identify ways to make analysis in the pre separation and post separation phase.
Should I have pulled tints, shades, primary and or secondary colors or a custom color? I have 360 degrees of Colors/Hues which I can pull or manipulate in way I want.
All of which is revealed when the black is pulled back. This the key step in the decision making process.
So analyzing the results in my opinion could be very beneficial. Not from a which product is better or worse but from looking at color, the analysis of it and separation of it.
Just my 2 cents..
I think that is the million dollar question! Can the seps be done better by using the custom mixes rather than the pure color? My thinking is that addition of black and white ink is muddying things up, but the sample size here is waay tooo small to make a even an educated guess. It is just a gut reaction at this point in time.
To make matters worse, if the 187 is made by adding black to 185 is there any benefit to printing with 187 since we are going to print the black anyways? Starting with 185 will give us a wider color gamut that can be created (when blended with other colors). On the other hand, if the predominant color is 187 than the halftone percentages of it should be wider and it should allow for the cleaner transitions and subtler shading. And to make matters worse, at least with the ink system we are using, 187 does not contain any black! So printing 185 might not get us right on the 187. And with the ink system we use, there are 14 colors (pigments) so the seps should really be done to include all of those if we were to recreate the full possible gamut (including the desired 187) of the mixing system (which is not even close to the visible spectrum even though it will be more than some and less than other color models). And the rabbit hole gets even deeper here. . . How closely can the mixing system approximate the colors we are after? What are the limitations of mixing colors in the system? If we need 20% red added to the yellow to create orange, will the same 20% of red create the correct shade of purple when added to blue or will it have to be mixed in higher percentage than it would be "by the book" due to the physical properties of the pigment particles? And finally, how would the program know how to use the 14 inks we have, in other words, it would need to have the mixing formula programed into it to know how to separate it properly.
HSB gets around that by using the pure colors on the 360 deg wheel and adjusting it with the black, white and saturation settings, but the more I think about it, more I see why the HSB seps are a little muddier than the hand separated stuff. As Tom mentioned, screenprinting (including separating) is an artform and that is why my gut reaction is "it has to be done by hand by somebody very knowledgable to get the very high end results!"
Thoughts, comments, suggestions???
pierre
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to clarify some of the previous, the 187 is made by mixing the white Red Blue shade and Red Yellow shade. To get bright colors created just by pigments without the black and white (that will reduce the pop), separating software would have to know the mixing ratio for the 187 and it would have to apply it when it is in the print. And this is for one color only! What about the thousands of other ones? Who is going to write the formulas and/or convert them to something separations software understands?
I think this is in part what Mark Coudray did with his program, but am not 100% sure. I know they spent a lot of time measuring and calculating the ink mixing and relationships between the colors, but I don't really know what that time was spent on. Maybe he can chime in here. . .
pierre
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Great posts pierre,
And we really should do some investigations around this I do believe that if you have 14 colors you can get some vibrancy that you may not get with some blends. But then again if you do not have 14 colors and still want to print full color then blends and lower numbers of color would be the only way. We have seen that things like how the halftones are are set can also make a huge difference in what happens with a blend and its vibrancy.
Bottom line we need to get some printing tests done around all this and look at the results.
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and it actually gets more complicated . . . Even if there were 14 colors available on the press and we spent the time to take all those readings and enter all that data into some system, how in the world do you create a color model based on your pigments and who then writes the mathe that calculates when/how to apply each formula? And then, if one of the readings is off, seps in that area will not be linearly out of whack, but somewhat random, so the localized patch with the off color would have to be adjusted separately from the rest of the image. in other words, formulation for that shade would have to be corrected, and the image would have to be reseparated. Right now, the seps we get from Dan are pretty linear. If we need more red, we usually bump the whole screen and everything falls into place. With a bad reading entered into the formula, it would just have a patch with bad color and would most likely require burning at least one if not multiple screens.
pierre
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Actually and this my sound like it is out there... But because we are dealing with math I see us being very close to what you just outlined within a year. Not with every detail you have listed but very close. Because color values and densities in the digital space can be scanned based on numerical values which Jeff just started playing with that and has a path to making it work. So smart separations are on the horizon for sure. But all based around HSB color which in theory could be tied into pigments but I am not sure if will get it that far. But being able to scan the color and present smart options for the separation is possible.
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Pierre asked me to take a look at this discussion and add my two cents worth. For me, it's a trip back in time. We wrestled with these issues extensively in '94-'95 and the realization that Photoshop would never be able to address the core underlying separation issues dealing with chromatic and achromatic gray balance. This is why ICISS was developed. Photoshop does not possess the core engine to address nChannel separations where n is the number of Channels and each channel represents THE SPECIFIC COLOR COORDINANTS OF THE PRINTING INK.
Where I see separation models failing, and it is happens all the time, is where the nChannel color position is established based on a numerical value that IS NOT representative of the ink being printed. This is one of the primary causes for color shifting on press compared to the sep. The more saturated and pure the color used for the channel separation, the greater the mismatch. So, with that being said, I would like to spend a couple of minutes on the points Pierre was making about using 187 as a primary or adding black to 185 to make the 187.
First a bit of color theory, all based on HSB because it is definitely the most understandable and intuituve of the color spaces. Every color has the theretical possibility of having 100% Brightness and 100% Saturation. That is theory. In reality, we cannot achieve this for two reasons. The first is that our visual sensory perception does not allow us to render full satuation at very high or very low Brightness levels. As the Brightness drops, the saturations moves closer and closer to black until we are no longer able to perceive the color and we only see black. The same is true for very high Brightness values as we move toward white.
It is important to note that this is NONLINEAR meaning that every color has a different perception profile (how we perceive the color in our brains.) This is what makes the math so incredibly difficult to calculate. It is essentiall 3D Matrix Calculus where we have a different function for every hue angle. In ICISS we set it up to measure and calculate to the first decimal place or 3600 different color transforms that interact in 3D. It was so involved 2 PhD mathematicians were brought in as consultants to interperet the actual printing data into an algorithm that would accurately render the complexity. I only bring this up to illustrate where the discussion eventually led to the realization this wasn't going to be solved with the tools inside PS.
Now back to the discussion using Pierre's example. If you cannot achieve a color with a natural pigment, you have to find a way to darken the color and still preserve as much of the color as possible. It will be easier to understand if you define "muddiness" as the addition of gray or desaturation of color to gray. Since we cannot preserve the saturation, any addition of gray will desaturate the color, adding grayness or muddiness to the color.
The two ways to desaturate are chromatically and achromatically. Chromatic desaturation is the addition of the complemenatry color or the mixing of a Hue 180° opposed to the color you are mixing into it. So when Pierre is Using Blue Shade Red and Yellow Shade Red to get his 187, what he is really doing is combining the Blue Shade component and the Yellow Shade component (complements eg 60° and 240° ) to make a chromatic gray that darkens the Red. This is the simple explanation since the amount of shift off the pure Hue is different for the BS Red than it is for the YS Red. A colorimeter reading of each pigment is necessary to determine exactly how much of a shift has occurred for each of the pigments based on the color strength or density of each pigment. The darker the pigment, the more blue emphasis due to the physics of light scattter.
The other way to do this is Achromatically (a = Without, chromatic = color). This means replacing the chromatic complement with black. Essentially simplifying the equation by replacing two components with one. This has the same darkening and desaturating effect but with one big difference. As any artist will tell you, when you add black to any color you KILL the chromatic aspect of that color. So it is ALWAYS preferable to desaturate with the chromatic complement than to add black.
From a printing aspect the replacement of the complementatry color with black is called GCR. Gray Component Replacement where the Gray Component Replacement is Black. It is a fantastic tool for stabilizing tone shifting on press, but at the expense of color saturation, especially in the darker colors. Photoshop uses GCR on a wholesale basis, applying it to all colors universally. When you understand how all this works it's possible to design selective GCR for every Hue angle. Since it is just math and it's an algorithm with variables, we just define a variable for the coefficient of chromatic > achromatic replacement. This means we can have complementary replacement for a color like Yellow where the addition of black is destructive to the color ( Yellow + Black = perceived muddy green), or we can have 100% black replacement in dark blues and reds where the addition of black is less destructive to the color. We can also decide if we want to use achromatic black in neutral colors and chromatic black for darker colors, as well was where the transition will occur between light and dark. All in all, a lot to think about and even more to model and calculate. It's like a rabbit hole, once you go down it, you keep on going.
Where all this becomes super important are in the pastel colors. We know this most commonly as the complex natural fleshtones. The addition of black in pastel colors is EXTREMELY destructive and desaturating to the color. This is were muddiness is exaggerated ten fold (literally because our eye is at least 10x more sensitive to tone and color changes in pastels.) This is also the reason almost all atttempts at rendering natural complex fleshtone fail. Anyone who has tried to deal with this or florals, animal fur (chromatic grays,) early sunrises, or pastel neutrals like beach sand, etc. knows this well.
Color is so much like learning to appreciate fine wine. In the beginning you can tell the difference between the broad categories white and red. You will typically prefer sweeter wines (saturation differentation). As you mature and develop your sensory skills you will be able to differentiate the varieties in each area (hue differentation.) Ultimately you will be able to detect the subtile differences between lightness (whites and rosé) and heavy (reds) [Brightness.] The very, very fine diffenences we often joke about (hints of tobacco, vanilla, plum, and razzberry etc) are really the super refined percepts of combining all elements together.
In color, it is not just the numerics. It is perceptual. Things like simultaneous contrast and nonlinear tone sensitivity are extremely difficult to model and add yet another dimension to the separation element. And then their is the psychological influence of color on mood that shifts the perception independently of the math (I was so mad I saw Red, or I'm feeling a little Blue today.) There is a reason color is used in advertising and architecture to effect mood. It all comes into play.
So where does all this leave us? Essentially the more tools we can build in as addressible variables, the better we can interpret color based on intended audience and the intended viewing environment. There is no universal solution, only the tools to interpret. High end color will always be edited. You cannot standardize it. Standardization = commoditization. So Dan, you are safe and will always be safe in this arena.
When you look at a true master like Andy Anderson, you realize this is a neverending quest for the ultimate reproduction. When you seek to render the transluscent luminence of a youthful skintone or the subtle reflection off a metallic or transparent color surface, you realize just how amazing our brain is at interpreting color and why any of us who have spent our lives in search of the answers will never be satisfied in our quest.
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Very well stated Mark. Thoughts on how percentage tone underbases can affect a single color? At Oats and Winterland this was critical to achieve CD cover illustration. Same with Harlequin however they would offer the same graphic on a myriad of blank colors and we occaisionally would experience shifting. My guy always insists on knowing the closest PMS color of dyed goods as this is his canvass.
He is a photoshop separator.
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Thanks for the post DrDot this has been quite a journey and we are still learning every single day in many different arenas. From the color spaces, to the models to the applications and screen printing. I have to say that for me coming to understand HSB working with a decent color space has been revolutionary.
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Tony,
Underbasing is another really complex idea. And once again, the solutions out there are all over the place. Underbasing works best with the HSB model (surprise.) The difference between Brightness and Value is Brightness is based on emissivity and Value is based on reflectance. Think of emissivity as how much light is being emitted. So for a computer pixel 100% birghtness means 100% power to the pixel. So we want to put 100% color behind 100% brightness color values. If you want to see the radical differnce between Brightness and Value calculations use the color picker in Photoshop and compare hs B value with L ab for a color like 185 Red. That is the simple answer, but it gets more complex, naturally that rabbit hole again
When you have a wet white under or over a color, you are desaturating toward white. In order to maintain saturation, you need variying degrees of dry white and wet with. So the transform is really two dimensional. The first dimension is to preserve the brightness and the second to preserve saturation. So two colors with 100% brightness will have dry white under the 100% saturation and wet whites behind the high brightness but decreasinging saturation colors. Again, this benefits from having the ability to create selective underbasing by color in the separation.
As a guide in picking colors for your separtion. My experience has been the best gamut results come when the B value is greater than 60%.
This type of underbase can be created in Photoshop if you use the HSB filter. It is getting harder and harder to find and to my knowledge is not available for 16 bit color calculation. That means it is only available for CS5 and lower. If anyone knows differently, I would really like to know about it.
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:'( Man you guys make my head hurt!
I have a solution throw some 4cp color inks in the screen and call it a day! Seriously just kidding of course.
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Tony,
Underbasing is another really complex idea. And once again, the solutions out there are all over the place. Underbasing works best with the HSB model (surprise.) The difference between Brightness and Value is Brightness is based on emissivity and Value is based on reflectance. Think of emissivity as how much light is being emitted. So for a computer pixel 100% birghtness means 100% power to the pixel. So we want to put 100% color behind 100% brightness color values. If you want to see the radical differnce between Brightness and Value calculations use the color picker in Photoshop and compare hs B value with L ab for a color like 185 Red. That is the simple answer, but it gets more complex, naturally that rabbit hole again
When you have a wet white under or over a color, you are desaturating toward white. In order to maintain saturation, you need variying degrees of dry white and wet with. So the transform is really two dimensional. The first dimension is to preserve the brightness and the second to preserve saturation. So two colors with 100% brightness will have dry white under the 100% saturation and wet whites behind the high brightness but decreasinging saturation colors. Again, this benefits from having the ability to create selective underbasing by color in the separation.
As a guide in picking colors for your separtion. My experience has been the best gamut results come when the B value is greater than 60%.
This type of underbase can be created in Photoshop if you use the HSB filter. It is getting harder and harder to find and to my knowledge is not available for 16 bit color calculation. That means it is only available for CS5 and lower. If anyone knows differently, I would really like to know about it.
Here's a link to the optional plug-ins for CS5 32 and 64 bit versions:
http://www.adobe.com/support/downloads/detail.jsp?ftpID=4688 (http://www.adobe.com/support/downloads/detail.jsp?ftpID=4688)
The HSB filter is inside the Optional MultiPlugin.8BF
That said, I have no idea how to use it!! How would you use it to create a great underbase?
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I am lovin this thread now... 8) But I would like to try and see if we can keep it simple for those that do not get all the scientific stuff. Which is a tall order I know. Maybe I will start another thread so we can try to break this down into simpler terms.
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Tis is the best example of a percentage tone UB in PS that I had laying around. Most apparent in the shirt and hair but you get the idea. And yes there is blue in the hair. The UB was discharge
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Great looking print.. One of things I have noticed over the last year of looking at things in HSB is that color does get into places you would not think it would be. Especially with the reflections from the environment the photos where taken in. We have been playing with allot of 3D stuff lately and in those environments it is really obvious what can be going on with the light.
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With HSB, if there is color there, it will get pulled into the appropriate channel. When all this was going down, I found myself seeking out museums and studying paintings for hours trying to develop and awareness and understanding of what was going on. When you really look at a Monet or Rembrandt, or any of the impressionist painters work, you immediately get it. At that time I was lucky enough to be traveling about every other week and found myself in some amazing cities with fantastic museums. The National Gallery in Washington DC, Art Institute in Chicago, Salvador Dali museum in St Petersburg, Fl. Those were incredible times of discovery and enlightenment. Sadly, 99% of printers never get past the basics and do not experience the satisfaction and accomplishment of faithful color reproduction. For the majority in this indusry it is all about how fast and how cheap it can be done. Close enough is never close enough, but it is commercially acceptable. This thread and this forum in particular are a move in the right direction.
There's nothing simple or fast about understanding and learning to "See" color. Until you can look at a very, very pastel neutral grey and be able to see the 2% or 3% color cast or look at a shadow and "see" the complement of the color of light in the shadow, you will never appreciate the possibilities. I'm not being critical but I think most of you know what I'm talking about. Very few want to put in the time, effort, and yes, hard work to really perfect their craft. Digital makes it worse because everyone thinks it's instant everything.
The beauty about really high end color is that the results can be so good, you literally can't put a finger on what makes it looks so great. The underlying subetlies give the color a richness and quality that you're immediately aware of.
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Yeah it is so true.. I mean I look at everything with HSB eyes all the time now. I have by no means perfected it and sometimes I just sit here sepping manually 3d renders and photos and things I find online. Its seems as though the deeper you go the easier it is to understand. Not that I would consider myself a master by any means but I would have never imagined how easy it can be when you get some basic understanding. Which is the intuitive part of HSB.
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I will find time to respond, I will find time to respond . . . . . . buried with artwork today. Still working on the films for tomorrow. <chanting> I will find time to respond, I will find time to respond . . .
pierre
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I was just thinking I do not want to get to far away from my life raft the water is getting pretty deep around here. Looking forward to your post pierre
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The water is deep and warm. DIVE IN!
Wow. Great stuff. Good thread. For now, I don't have much to contribute.
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I was just thinking I do not want to get to far away from my life raft the water is getting pretty deep around here. Looking forward to your post pierre
you give me too much credit, I just have a million questions and very little actual knowledge to contribute. . . Mark is doing the heavy lifting here and it is just AWESOME to get this kind of information!
pierre
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you give me too much credit, I just have a million questions and very little actual knowledge to contribute. . . Mark is doing the heavy lifting here and it is just AWESOME to get this kind of information!
pierre
I was referring to Marks posts and wait till Jeff comes in its gonna get really deep around here. It is really cool because I taught Jeff 8 years ago now Jeff teaches me and I take that and teach. I am a teacher that is the gift that compliments my artistic gifts. Just like the colors that we are talking about. So with Jeff watching the harvest come back is just.. well there are no words for that.
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Actually and this my sound like it is out there... But because we are dealing with math I see us being very close to what you just outlined within a year. Not with every detail you have listed but very close. Because color values and densities in the digital space can be scanned based on numerical values which Jeff just started playing with that and has a path to making it work. So smart separations are on the horizon for sure. But all based around HSB color which in theory could be tied into pigments but I am not sure if will get it that far. But being able to scan the color and present smart options for the separation is possible.
I will add here, that we have both the transmissive and reflective densitometer and spectometer. Dialing everything in and getting much closer to the bottom of what our inks are doing and why, is on my list of things to do. Not the next thing, but few steps down the line. I think Mark's software allows some sort of correction (if I remember right) to tweak it for the user's ink system. When Mark was explaining all the features of the software, it was waaaay over my head so I probably misunderstood a lot. If Mark can find some time, it would be great to have a post showing the capabilities and features of ICISS.
How and what exactly to do with the equipment we have is still a little unclear. This thread is definitely shaping a path that leads to understanding what is really going on. I could randomly start taking the readings of what colors are doing when printed, but without truly understanding what is going on, it would be like whacking around hoping to hit the piñata! Systematic and continuous advancement leads to progress, randomly flailing around just makes one tired!
pierre
pierre
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One other thing.. lets leave opinions and bias outside this has the potential to be a historic thread in this Industry. We have questions we have understanding it is all here right now. Lets be open, honest and lets share.
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Interesting stuff. Thanks so much for chiming in, Mr. Coudray. I didn't expect to see such an interesting connection drawn on this topic.
The impressionists had some rather interesting techniques with complements--as I understand it, the pure (unmixed) colors are what enabled their realistic interplay of light and shadow, as well as avoiding the pitfalls of the subtractive color model he was (and we are) stuck with.
If you look closely at something like A Sunday on Le Grande Jatte, you don't see a whole lot of black anywhere besides black clothes and the black dog, but the shadows are mostly complementary colors, as opposed to black.
I think It would be extremely interesting to see what an HSB style of sep does to a piece like that.
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Interesting stuff. Thanks so much for chiming in, Mr. Coudray. I didn't expect to see such an interesting connection drawn on this topic.
The impressionists had some rather interesting techniques with complements--as I understand it, the pure (unmixed) colors are what enabled their realistic interplay of light and shadow, as well as avoiding the pitfalls of the subtractive color model he was (and we are) stuck with.
If you look closely at something like A Sunday on Le Grande Jatte, you don't see a whole lot of black anywhere besides black clothes and the black dog, but the shadows are mostly complementary colors, as opposed to black.
I think It would be extremely interesting to see what an HSB style of sep does to a piece like that.
Interesting which one of these digital representations is the closest?
http://www.google.com/search?hl=en&site=imghp&tbm=isch&source=hp&biw=1120&bih=530&q=A+Sunday+on+Le+Grande+Jatte&oq=A+Sunday+on+Le+Grande+Jatte&gs_l=img.12..0i10i24.1906.1906.0.3509.1.1.0.0.0.0.210.210.2-1.1.0...0.0...1ac.1.9.img.b16Lh2OiHt8 (http://www.google.com/search?hl=en&site=imghp&tbm=isch&source=hp&biw=1120&bih=530&q=A+Sunday+on+Le+Grande+Jatte&oq=A+Sunday+on+Le+Grande+Jatte&gs_l=img.12..0i10i24.1906.1906.0.3509.1.1.0.0.0.0.210.210.2-1.1.0...0.0...1ac.1.9.img.b16Lh2OiHt8)
I am stumped.... ???
Edit.. its like skittles that dress in every color in the rainbow. Purple, blue, brown, green etc.
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Pierre asked me to take a look at this discussion and add my two cents worth. For me, it's a trip back in time. We wrestled with these issues extensively in '94-'95 and the realization that Photoshop would never be able to address the core underlying separation issues dealing with chromatic and achromatic gray balance. This is why ICISS was developed. Photoshop does not possess the core engine to address nChannel separations where n is the number of Channels and each channel represents THE SPECIFIC COLOR COORDINANTS OF THE PRINTING INK.
Where I see separation models failing, and it is happens all the time, is where the nChannel color position is established based on a numerical value that IS NOT representative of the ink being printed. This is one of the primary causes for color shifting on press compared to the sep. The more saturated and pure the color used for the channel separation, the greater the mismatch. So, with that being said, I would like to spend a couple of minutes on the points Pierre was making about using 187 as a primary or adding black to 185 to make the 187.
First a bit of color theory, all based on HSB because it is definitely the most understandable and intuituve of the color spaces. Every color has the theretical possibility of having 100% Brightness and 100% Saturation. That is theory. In reality, we cannot achieve this for two reasons. The first is that our visual sensory perception does not allow us to render full satuation at very high or very low Brightness levels. As the Brightness drops, the saturations moves closer and closer to black until we are no longer able to perceive the color and we only see black. The same is true for very high Brightness values as we move toward white.
It is important to note that this is NONLINEAR meaning that every color has a different perception profile (how we perceive the color in our brains.) This is what makes the math so incredibly difficult to calculate. It is essentiall 3D Matrix Calculus where we have a different function for every hue angle. In ICISS we set it up to measure and calculate to the first decimal place or 3600 different color transforms that interact in 3D. It was so involved 2 PhD mathematicians were brought in as consultants to interperet the actual printing data into an algorithm that would accurately render the complexity. I only bring this up to illustrate where the discussion eventually led to the realization this wasn't going to be solved with the tools inside PS.
Now back to the discussion using Pierre's example. If you cannot achieve a color with a natural pigment, you have to find a way to darken the color and still preserve as much of the color as possible. It will be easier to understand if you define "muddiness" as the addition of gray or desaturation of color to gray. Since we cannot preserve the saturation, any addition of gray will desaturate the color, adding grayness or muddiness to the color.
The two ways to desaturate are chromatically and achromatically. Chromatic desaturation is the addition of the complemenatry color or the mixing of a Hue 180° opposed to the color you are mixing into it. So when Pierre is Using Blue Shade Red and Yellow Shade Red to get his 187, what he is really doing is combining the Blue Shade component and the Yellow Shade component (complements eg 60° and 240° ) to make a chromatic gray that darkens the Red. This is the simple explanation since the amount of shift off the pure Hue is different for the BS Red than it is for the YS Red. A colorimeter reading of each pigment is necessary to determine exactly how much of a shift has occurred for each of the pigments based on the color strength or density of each pigment. The darker the pigment, the more blue emphasis due to the physics of light scattter.
The other way to do this is Achromatically (a = Without, chromatic = color). This means replacing the chromatic complement with black. Essentially simplifying the equation by replacing two components with one. This has the same darkening and desaturating effect but with one big difference. As any artist will tell you, when you add black to any color you KILL the chromatic aspect of that color. So it is ALWAYS preferable to desaturate with the chromatic complement than to add black.
From a printing aspect the replacement of the complementatry color with black is called GCR. Gray Component Replacement where the Gray Component Replacement is Black. It is a fantastic tool for stabilizing tone shifting on press, but at the expense of color saturation, especially in the darker colors. Photoshop uses GCR on a wholesale basis, applying it to all colors universally. When you understand how all this works it's possible to design selective GCR for every Hue angle. Since it is just math and it's an algorithm with variables, we just define a variable for the coefficient of chromatic > achromatic replacement. This means we can have complementary replacement for a color like Yellow where the addition of black is destructive to the color ( Yellow + Black = perceived muddy green), or we can have 100% black replacement in dark blues and reds where the addition of black is less destructive to the color. We can also decide if we want to use achromatic black in neutral colors and chromatic black for darker colors, as well was where the transition will occur between light and dark. All in all, a lot to think about and even more to model and calculate. It's like a rabbit hole, once you go down it, you keep on going.
Where all this becomes super important are in the pastel colors. We know this most commonly as the complex natural fleshtones. The addition of black in pastel colors is EXTREMELY destructive and desaturating to the color. This is were muddiness is exaggerated ten fold (literally because our eye is at least 10x more sensitive to tone and color changes in pastels.) This is also the reason almost all atttempts at rendering natural complex fleshtone fail. Anyone who has tried to deal with this or florals, animal fur (chromatic grays,) early sunrises, or pastel neutrals like beach sand, etc. knows this well.
Color is so much like learning to appreciate fine wine. In the beginning you can tell the difference between the broad categories white and red. You will typically prefer sweeter wines (saturation differentation). As you mature and develop your sensory skills you will be able to differentiate the varieties in each area (hue differentation.) Ultimately you will be able to detect the subtile differences between lightness (whites and rosé) and heavy (reds) [Brightness.] The very, very fine diffenences we often joke about (hints of tobacco, vanilla, plum, and razzberry etc) are really the super refined percepts of combining all elements together.
In color, it is not just the numerics. It is perceptual. Things like simultaneous contrast and nonlinear tone sensitivity are extremely difficult to model and add yet another dimension to the separation element. And then their is the psychological influence of color on mood that shifts the perception independently of the math (I was so mad I saw Red, or I'm feeling a little Blue today.) There is a reason color is used in advertising and architecture to effect mood. It all comes into play.
So where does all this leave us? Essentially the more tools we can build in as addressible variables, the better we can interpret color based on intended audience and the intended viewing environment. There is no universal solution, only the tools to interpret. High end color will always be edited. You cannot standardize it. Standardization = commoditization. So Dan, you are safe and will always be safe in this arena.
When you look at a true master like Andy Anderson, you realize this is a neverending quest for the ultimate reproduction. When you seek to render the transluscent luminence of a youthful skintone or the subtle reflection off a metallic or transparent color surface, you realize just how amazing our brain is at interpreting color and why any of us who have spent our lives in search of the answers will never be satisfied in our quest.
few thoughts and questions. . .
As I have not done any scientific research and poses no relevant data (short of very subjective observations), anything contributed will have to be an opinion or a question. Mark is the one with hard facts here and I am willing to take his word as gospel until there is an opportunity to do the research and get data that contradicts what he is saying (which is not very likely to happen. The contradicting data part that is).
Reading this post, the first question I have is about the blue emphasis with the darker pigments. Mark, is there a name for this effect and where do we get more info?
When you say, there is an achromatic and chromatic variable (specifying the point of shifting from a to chromatic and vice versa) are you talking about your software or Photoshop? I know you can specify the black generation in the CMYK settings, but can this be done for other colorspace models? And while at it, what is a dark yellow anyways? It seems, no matter what is done to it, it always shifts to one of its neighbors, green or red.
what about using out of gamut primaries for separations? 240/100/100 is showing as out of range in Photoshop, but is that the limitation of the colorspace, physics or the software? If 240/100/100 is not achievable, then the only solution to correct separations is the nChannel model!
In color, it is not just the numerics. It is perceptual
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At what point could it be said that it is not perceptual any more? It seems to me that ultimately there are 1's and 0's and that is the art we are dealing with today. It is specified very precisely, and just because somebody perceives it differently it does not change the underlying data. It seems to me that as deep as this rabbit hole is, eventually there is a hard bottom (linear system assumption). Once down at the 0's and 1's level, there is no more interpreting. The data is not open to individual perceptions if it is manipulated by math rather than subjective opinions (since math has objective rules only). What is it going to take to get to that point? Are we all gonna have to work in the same colorspace that is independent of the media? Is peeling back all these layers of interference the answer to getting the true result? Is that even a possibility or is the model non linear and all the results are just approximations? If the model is linear, then there is an answer and any deviation is an interpretation, either personal or by request, but an interpretation none the less.
time to go though, I'll have to tackle the second part of this tomorrow. . .
pierre
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The water is deep and warm. DIVE IN!
Wow. Great stuff. Good thread. For now, I don't have much to contribute.
You have allot to contribute Dan decades of experience and well you know. You are DTD I may be strong about trying to get this out but I have always respected your work. 8) Sometimes it may not come across that way.. but getting these things out is very important.
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Pierre asked me to take a look at this discussion and add my two cents worth. For me, it's a trip back in time. We wrestled with these issues extensively in '94-'95 and the realization that Photoshop would never be able to address the core underlying separation issues dealing with chromatic and achromatic gray balance. This is why ICISS was developed. Photoshop does not possess the core engine to address nChannel separations where n is the number of Channels and each channel represents THE SPECIFIC COLOR COORDINANTS OF THE PRINTING INK.
Where I see separation models failing, and it is happens all the time, is where the nChannel color position is established based on a numerical value that IS NOT representative of the ink being printed. This is one of the primary causes for color shifting on press compared to the sep. The more saturated and pure the color used for the channel separation, the greater the mismatch. So, with that being said, I would like to spend a couple of minutes on the points Pierre was making about using 187 as a primary or adding black to 185 to make the 187.
First a bit of color theory, all based on HSB because it is definitely the most understandable and intuituve of the color spaces. Every color has the theretical possibility of having 100% Brightness and 100% Saturation. That is theory. In reality, we cannot achieve this for two reasons. The first is that our visual sensory perception does not allow us to render full satuation at very high or very low Brightness levels. As the Brightness drops, the saturations moves closer and closer to black until we are no longer able to perceive the color and we only see black. The same is true for very high Brightness values as we move toward white.
It is important to note that this is NONLINEAR meaning that every color has a different perception profile (how we perceive the color in our brains.) This is what makes the math so incredibly difficult to calculate. It is essentiall 3D Matrix Calculus where we have a different function for every hue angle. In ICISS we set it up to measure and calculate to the first decimal place or 3600 different color transforms that interact in 3D. It was so involved 2 PhD mathematicians were brought in as consultants to interperet the actual printing data into an algorithm that would accurately render the complexity. I only bring this up to illustrate where the discussion eventually led to the realization this wasn't going to be solved with the tools inside PS.
Now back to the discussion using Pierre's example. If you cannot achieve a color with a natural pigment, you have to find a way to darken the color and still preserve as much of the color as possible. It will be easier to understand if you define "muddiness" as the addition of gray or desaturation of color to gray. Since we cannot preserve the saturation, any addition of gray will desaturate the color, adding grayness or muddiness to the color.
The two ways to desaturate are chromatically and achromatically. Chromatic desaturation is the addition of the complemenatry color or the mixing of a Hue 180° opposed to the color you are mixing into it. So when Pierre is Using Blue Shade Red and Yellow Shade Red to get his 187, what he is really doing is combining the Blue Shade component and the Yellow Shade component (complements eg 60° and 240° ) to make a chromatic gray that darkens the Red. This is the simple explanation since the amount of shift off the pure Hue is different for the BS Red than it is for the YS Red. A colorimeter reading of each pigment is necessary to determine exactly how much of a shift has occurred for each of the pigments based on the color strength or density of each pigment. The darker the pigment, the more blue emphasis due to the physics of light scattter.
The other way to do this is Achromatically (a = Without, chromatic = color). This means replacing the chromatic complement with black. Essentially simplifying the equation by replacing two components with one. This has the same darkening and desaturating effect but with one big difference. As any artist will tell you, when you add black to any color you KILL the chromatic aspect of that color. So it is ALWAYS preferable to desaturate with the chromatic complement than to add black.
From a printing aspect the replacement of the complementatry color with black is called GCR. Gray Component Replacement where the Gray Component Replacement is Black. It is a fantastic tool for stabilizing tone shifting on press, but at the expense of color saturation, especially in the darker colors. Photoshop uses GCR on a wholesale basis, applying it to all colors universally. When you understand how all this works it's possible to design selective GCR for every Hue angle. Since it is just math and it's an algorithm with variables, we just define a variable for the coefficient of chromatic > achromatic replacement. This means we can have complementary replacement for a color like Yellow where the addition of black is destructive to the color ( Yellow + Black = perceived muddy green), or we can have 100% black replacement in dark blues and reds where the addition of black is less destructive to the color. We can also decide if we want to use achromatic black in neutral colors and chromatic black for darker colors, as well was where the transition will occur between light and dark. All in all, a lot to think about and even more to model and calculate. It's like a rabbit hole, once you go down it, you keep on going.
Where all this becomes super important are in the pastel colors. We know this most commonly as the complex natural fleshtones. The addition of black in pastel colors is EXTREMELY destructive and desaturating to the color. This is were muddiness is exaggerated ten fold (literally because our eye is at least 10x more sensitive to tone and color changes in pastels.) This is also the reason almost all atttempts at rendering natural complex fleshtone fail. Anyone who has tried to deal with this or florals, animal fur (chromatic grays,) early sunrises, or pastel neutrals like beach sand, etc. knows this well.
Color is so much like learning to appreciate fine wine. In the beginning you can tell the difference between the broad categories white and red. You will typically prefer sweeter wines (saturation differentation). As you mature and develop your sensory skills you will be able to differentiate the varieties in each area (hue differentation.) Ultimately you will be able to detect the subtile differences between lightness (whites and rosé) and heavy (reds) [Brightness.] The very, very fine diffenences we often joke about (hints of tobacco, vanilla, plum, and razzberry etc) are really the super refined percepts of combining all elements together.
In color, it is not just the numerics. It is perceptual. Things like simultaneous contrast and nonlinear tone sensitivity are extremely difficult to model and add yet another dimension to the separation element. And then their is the psychological influence of color on mood that shifts the perception independently of the math (I was so mad I saw Red, or I'm feeling a little Blue today.) There is a reason color is used in advertising and architecture to effect mood. It all comes into play.
So where does all this leave us? Essentially the more tools we can build in as addressible variables, the better we can interpret color based on intended audience and the intended viewing environment. There is no universal solution, only the tools to interpret. High end color will always be edited. You cannot standardize it. Standardization = commoditization. So Dan, you are safe and will always be safe in this arena.
When you look at a true master like Andy Anderson, you realize this is a neverending quest for the ultimate reproduction. When you seek to render the transluscent luminence of a youthful skintone or the subtle reflection off a metallic or transparent color surface, you realize just how amazing our brain is at interpreting color and why any of us who have spent our lives in search of the answers will never be satisfied in our quest.
few thoughts and questions. . .
As I have not done any scientific research and poses no relevant data (short of very subjective observations), anything contributed will have to be an opinion or a question. Mark is the one with hard facts here and I am willing to take his word as gospel until there is an opportunity to do the research and get data that contradicts what he is saying (which is not very likely to happen. The contradicting data part that is).
Reading this post, the first question I have is about the blue emphasis with the darker pigments. Mark, is there a name for this effect and where do we get more info?
When you say, there is an achromatic and chromatic variable (specifying the point of shifting from a to chromatic and vice versa) are you talking about your software or Photoshop? I know you can specify the black generation in the CMYK settings, but can this be done for other colorspace models? And while at it, what is a dark yellow anyways? It seems, no matter what is done to it, it always shifts to one of its neighbors, green or red.
what about using out of gamut primaries for separations? 240/100/100 is showing as out of range in Photoshop, but is that the limitation of the colorspace, physics or the software? If 240/100/100 is not achievable, then the only solution to correct separations is the nChannel model!
In color, it is not just the numerics. It is perceptual
.
At what point could it be said that it is not perceptual any more? It seems to me that ultimately there are 1's and 0's and that is the art we are dealing with today. It is specified very precisely, and just because somebody perceives it differently it does not change the underlying data. It seems to me that as deep as this rabbit hole is, eventually there is a hard bottom (linear system assumption). Once down at the 0's and 1's level, there is no more interpreting. The data is not open to individual perceptions if it is manipulated by math rather than subjective opinions (since math has objective rules only). What is it going to take to get to that point? Are we all gonna have to work in the same colorspace that is independent of the media? Is peeling back all these layers of interference the answer to getting the true result? Is that even a possibility or is the model non linear and all the results are just approximations? If the model is linear, then there is an answer and any deviation is an interpretation, either personal or by request, but an interpretation none the less.
time to go though, I'll have to tackle the second part of this tomorrow. . .
pierre
I think Jeffs test pattern/color wheel would be a great way to start it has a good representation of many hues/colors all kinds with saturation and brightness. We have not printed it yet but I think that or something close to it would be the best graphic to make indepth analysis with. Maybe in a 6 hues and a 12 tints pull which would give us some data relating to color quality and vibrancy based on number colors and saturation/brightness across a number of blends and colors.
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Pierre asked me to take a look at this discussion and add my two cents worth. For me, it's a trip back in time. We wrestled with these issues extensively in '94-'95 and the realization that Photoshop would never be able to address the core underlying separation issues dealing with chromatic and achromatic gray balance. This is why ICISS was developed. Photoshop does not possess the core engine to address nChannel separations where n is the number of Channels and each channel represents THE SPECIFIC COLOR COORDINANTS OF THE PRINTING INK.
Where I see separation models failing, and it is happens all the time, is where the nChannel color position is established based on a numerical value that IS NOT representative of the ink being printed. This is one of the primary causes for color shifting on press compared to the sep. The more saturated and pure the color used for the channel separation, the greater the mismatch. So, with that being said, I would like to spend a couple of minutes on the points Pierre was making about using 187 as a primary or adding black to 185 to make the 187.
First a bit of color theory, all based on HSB because it is definitely the most understandable and intuituve of the color spaces. Every color has the theretical possibility of having 100% Brightness and 100% Saturation. That is theory. In reality, we cannot achieve this for two reasons. The first is that our visual sensory perception does not allow us to render full satuation at very high or very low Brightness levels. As the Brightness drops, the saturations moves closer and closer to black until we are no longer able to perceive the color and we only see black. The same is true for very high Brightness values as we move toward white.
It is important to note that this is NONLINEAR meaning that every color has a different perception profile (how we perceive the color in our brains.) This is what makes the math so incredibly difficult to calculate. It is essentiall 3D Matrix Calculus where we have a different function for every hue angle. In ICISS we set it up to measure and calculate to the first decimal place or 3600 different color transforms that interact in 3D. It was so involved 2 PhD mathematicians were brought in as consultants to interperet the actual printing data into an algorithm that would accurately render the complexity. I only bring this up to illustrate where the discussion eventually led to the realization this wasn't going to be solved with the tools inside PS.
Now back to the discussion using Pierre's example. If you cannot achieve a color with a natural pigment, you have to find a way to darken the color and still preserve as much of the color as possible. It will be easier to understand if you define "muddiness" as the addition of gray or desaturation of color to gray. Since we cannot preserve the saturation, any addition of gray will desaturate the color, adding grayness or muddiness to the color.
The two ways to desaturate are chromatically and achromatically. Chromatic desaturation is the addition of the complemenatry color or the mixing of a Hue 180° opposed to the color you are mixing into it. So when Pierre is Using Blue Shade Red and Yellow Shade Red to get his 187, what he is really doing is combining the Blue Shade component and the Yellow Shade component (complements eg 60° and 240° ) to make a chromatic gray that darkens the Red. This is the simple explanation since the amount of shift off the pure Hue is different for the BS Red than it is for the YS Red. A colorimeter reading of each pigment is necessary to determine exactly how much of a shift has occurred for each of the pigments based on the color strength or density of each pigment. The darker the pigment, the more blue emphasis due to the physics of light scattter.
The other way to do this is Achromatically (a = Without, chromatic = color). This means replacing the chromatic complement with black. Essentially simplifying the equation by replacing two components with one. This has the same darkening and desaturating effect but with one big difference. As any artist will tell you, when you add black to any color you KILL the chromatic aspect of that color. So it is ALWAYS preferable to desaturate with the chromatic complement than to add black.
From a printing aspect the replacement of the complementatry color with black is called GCR. Gray Component Replacement where the Gray Component Replacement is Black. It is a fantastic tool for stabilizing tone shifting on press, but at the expense of color saturation, especially in the darker colors. Photoshop uses GCR on a wholesale basis, applying it to all colors universally. When you understand how all this works it's possible to design selective GCR for every Hue angle. Since it is just math and it's an algorithm with variables, we just define a variable for the coefficient of chromatic > achromatic replacement. This means we can have complementary replacement for a color like Yellow where the addition of black is destructive to the color ( Yellow + Black = perceived muddy green), or we can have 100% black replacement in dark blues and reds where the addition of black is less destructive to the color. We can also decide if we want to use achromatic black in neutral colors and chromatic black for darker colors, as well was where the transition will occur between light and dark. All in all, a lot to think about and even more to model and calculate. It's like a rabbit hole, once you go down it, you keep on going.
Where all this becomes super important are in the pastel colors. We know this most commonly as the complex natural fleshtones. The addition of black in pastel colors is EXTREMELY destructive and desaturating to the color. This is were muddiness is exaggerated ten fold (literally because our eye is at least 10x more sensitive to tone and color changes in pastels.) This is also the reason almost all atttempts at rendering natural complex fleshtone fail. Anyone who has tried to deal with this or florals, animal fur (chromatic grays,) early sunrises, or pastel neutrals like beach sand, etc. knows this well.
Color is so much like learning to appreciate fine wine. In the beginning you can tell the difference between the broad categories white and red. You will typically prefer sweeter wines (saturation differentation). As you mature and develop your sensory skills you will be able to differentiate the varieties in each area (hue differentation.) Ultimately you will be able to detect the subtile differences between lightness (whites and rosé) and heavy (reds) [Brightness.] The very, very fine diffenences we often joke about (hints of tobacco, vanilla, plum, and razzberry etc) are really the super refined percepts of combining all elements together.
In color, it is not just the numerics. It is perceptual. Things like simultaneous contrast and nonlinear tone sensitivity are extremely difficult to model and add yet another dimension to the separation element. And then their is the psychological influence of color on mood that shifts the perception independently of the math (I was so mad I saw Red, or I'm feeling a little Blue today.) There is a reason color is used in advertising and architecture to effect mood. It all comes into play.
So where does all this leave us? Essentially the more tools we can build in as addressible variables, the better we can interpret color based on intended audience and the intended viewing environment. There is no universal solution, only the tools to interpret. High end color will always be edited. You cannot standardize it. Standardization = commoditization. So Dan, you are safe and will always be safe in this arena.
When you look at a true master like Andy Anderson, you realize this is a neverending quest for the ultimate reproduction. When you seek to render the transluscent luminence of a youthful skintone or the subtle reflection off a metallic or transparent color surface, you realize just how amazing our brain is at interpreting color and why any of us who have spent our lives in search of the answers will never be satisfied in our quest.
few thoughts and questions. . .
As I have not done any scientific research and poses no relevant data (short of very subjective observations), anything contributed will have to be an opinion or a question. Mark is the one with hard facts here and I am willing to take his word as gospel until there is an opportunity to do the research and get data that contradicts what he is saying (which is not very likely to happen. The contradicting data part that is).
Reading this post, the first question I have is about the blue emphasis with the darker pigments. Mark, is there a name for this effect and where do we get more info?
When you say, there is an achromatic and chromatic variable (specifying the point of shifting from a to chromatic and vice versa) are you talking about your software or Photoshop? I know you can specify the black generation in the CMYK settings, but can this be done for other colorspace models? And while at it, what is a dark yellow anyways? It seems, no matter what is done to it, it always shifts to one of its neighbors, green or red.
what about using out of gamut primaries for separations? 240/100/100 is showing as out of range in Photoshop, but is that the limitation of the colorspace, physics or the software? If 240/100/100 is not achievable, then the only solution to correct separations is the nChannel model!
In color, it is not just the numerics. It is perceptual
.
At what point could it be said that it is not perceptual any more? It seems to me that ultimately there are 1's and 0's and that is the art we are dealing with today. It is specified very precisely, and just because somebody perceives it differently it does not change the underlying data. It seems to me that as deep as this rabbit hole is, eventually there is a hard bottom (linear system assumption). Once down at the 0's and 1's level, there is no more interpreting. The data is not open to individual perceptions if it is manipulated by math rather than subjective opinions (since math has objective rules only). What is it going to take to get to that point? Are we all gonna have to work in the same colorspace that is independent of the media? Is peeling back all these layers of interference the answer to getting the true result? Is that even a possibility or is the model non linear and all the results are just approximations? If the model is linear, then there is an answer and any deviation is an interpretation, either personal or by request, but an interpretation none the less.
time to go though, I'll have to tackle the second part of this tomorrow. . .
pierre
I think Jeffs test pattern/color wheel would be a great way to start it has a good representation of many hues/colors all kinds with saturation and brightness. We have not printed it yet but I think that or something close to it would be the best graphic to make indepth analysis with. Maybe in a 6 hues and a 12 tints pull which would give us some data relating to color quality and vibrancy based on number colors and saturation/brightness across a number of blends and colors.
email me the seps and I'll print it and take the spectrometer readings. While the color wheel would be nice to have, it would make it hard to take the readings. Make it blocks of at least 1x1" (and 2x2 would be better). let's say 12 wide and 14 tall.
pierre
p.s. I have no idea what kind of readings we'll get from the garment, but it should be worth a try.
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Let me get the file from Jeff I think some of detail may be to small in his current version but we can make a file that will basically give us the same info with bigger elements making it easier to examine the results. I will go over this with him and then get with you.
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few thoughts and questions. . .
As I have not done any scientific research and poses no relevant data (short of very subjective observations), anything contributed will have to be an opinion or a question. Mark is the one with hard facts here and I am willing to take his word as gospel until there is an opportunity to do the research and get data that contradicts what he is saying (which is not very likely to happen. The contradicting data part that is).
Reading this post, the first question I have is about the blue emphasis with the darker pigments. Mark, is there a name for this effect and where do we get more info?
When you say, there is an achromatic and chromatic variable (specifying the point of shifting from a to chromatic and vice versa) are you talking about your software or Photoshop? I know you can specify the black generation in the CMYK settings, but can this be done for other colorspace models? And while at it, what is a dark yellow anyways? It seems, no matter what is done to it, it always shifts to one of its neighbors, green or red.
what about using out of gamut primaries for separations? 240/100/100 is showing as out of range in Photoshop, but is that the limitation of the colorspace, physics or the software? If 240/100/100 is not achievable, then the only solution to correct separations is the nChannel model!
Chromatic gray can be made from any combination of colors. The definition of gray is R=G=B value, so a 50% neutral gray is 128, 128, 128. This is perfect neutral gray. If you have two colors that are numerically (H) separated by 180° you will get a perfect neutral gray (NG.) With the right mixing algorithm, you can make neutral gray from any 3 colors, or as many as you like for that matter. ICISS has the ability to make from any combination of colors and to transition to Black (Achromatic Gray) at any point. Most of you will be familiar with this concept in Photoshop>Color Settings>Custom CMYK>Black Generation. When set to Medium, you will note that the Black (here chromatic) is being made from pure CMYK until about the 25% tonal value when Black makes an appearance and increases progressively. The color component maxes out at 50% tonal gray and the Black continues to add in order to get the maximum full tonal gray scale.
Pay particular attention to the differences between the Cyan, Magenta, and Yellow values to make neutral gray. This demonstrates that we need less Yellow because each of the other colors has Yellow containation. The Magenta has up to 50% yellow shift from the ideal Magenta math point (300°) It also has some Cyan contaimination as well (9%- 11% typically.) The contamination of color in a primay is referred to as the "grayness" of the color and represents the natural complementary protion in the ink. For a typical Magenta the Grayness is 9%- 11% and the Hue Shift is 30%.
This is how a set of process colors positions is analyzed and it is what I used when I worked with Terry Kaiserman in 1991 to develop the Union TruTone Process ink set (still the best process ink set by far).
In color, it is not just the numerics. It is perceptual.
At what point could it be said that it is not perceptual any more? It seems to me that ultimately there are 1's and 0's and that is the art we are dealing with today. It is specified very precisely, and just because somebody perceives it differently it does not change the underlying data. It seems to me that as deep as this rabbit hole is, eventually there is a hard bottom (linear system assumption). Once down at the 0's and 1's level, there is no more interpreting. The data is not open to individual perceptions if it is manipulated by math rather than subjective opinions (since math has objective rules only). What is it going to take to get to that point? Are we all gonna have to work in the same colorspace that is independent of the media? Is peeling back all these layers of interference the answer to getting the true result? Is that even a possibility or is the model non linear and all the results are just approximations? If the model is linear, then there is an answer and any deviation is an interpretation, either personal or by request, but an interpretation none the less.
pierre
This is like saying, "If a tree falls in the forest, and there is no one there, is there still sound?" The answer is, of course there is sound. Perception is our ability to detect the presence of color. Perception changes under the view conditions, age and gender of the viewer, genetics, and a host of other factors. Look at the far right side of the color picker in PS. As any Hue of 100% S moves from from B = 100 to B=0%, at some point on YOUR monitor under YOUR viewing conditions YOU will no longer be able to perceive or detect color, even though the VERY low B% appears to be BLACK. This is one of the reasons HSB pulls such accurate seps. It is going for the color values and is delivering color information into the appropriate ink channel. Whether we can reproduce that color is dependent on the very best pigment we have to work with. So if you want 240°, 100, 100 - the very best you're going to get from a Pantone Color is 2736 (234, 83, 66). Any color with a value higher than the S or B value will be Out of Gamut. Interestingly, as you go up one step in the book to Pantone 2726, you will notice a HUE SHIFT to the Yellow Side of 4°, a DECREASE in Saturation and an INCREASE in Brightness. This illustrates a the yellow shift I spoke of earlier because there are less pigment molecules in a given space (lower density) and as a consequence, there is less light scatter and absorbsion resulting in more longer wavelength frequencies being reflected to our eye. We see the same efffect when we look at water in swimming pool from above, or the shallow areas of a tropical beach. Shallow=yellow cast, Deep = Red cast.
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Tony,
Underbasing is another really complex idea. And once again, the solutions out there are all over the place. Underbasing works best with the HSB model (surprise.)
This is a profound statement concerning HSB because we screen printers print with white allot. Which is partially why HSB is the perfect fit for us. White and white bases are something we deal with all the time and HSB is perfectly suited for the ways in which we use white.
HSB easier and uniquely suited to us. Allot of technical posts here but do not let that confuse you before all this is done I will break it all down into much easier terms in video.
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If Mark can find some time, it would be great to have a post showing the capabilities and features of ICISS.
How and what exactly to do with the equipment we have is still a little unclear. This thread is definitely shaping a path that leads to understanding what is really going on. I could randomly start taking the readings of what colors are doing when printed, but without truly understanding what is going on, it would be like whacking around hoping to hit the piñata! Systematic and continuous advancement leads to progress, randomly flailing around just makes one tired!
pierre
pierre
... so very sorry that the topic is frozen ...I want to know the possibility of ISISS - from the Maestro!
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If Mark can find some time, it would be great to have a post showing the capabilities and features of ICISS.
How and what exactly to do with the equipment we have is still a little unclear. This thread is definitely shaping a path that leads to understanding what is really going on. I could randomly start taking the readings of what colors are doing when printed, but without truly understanding what is going on, it would be like whacking around hoping to hit the piñata! Systematic and continuous advancement leads to progress, randomly flailing around just makes one tired!
pierre
pierre
... so very sorry that the topic is frozen ...I want to know the possibility of ISISS - from the Maestro!
Not frozen, just stalled. As was mentioned, the Doctor doesn't have as much spare time as many of us do.
Who knows? Perhaps a PM or email could get it going again and answer some specifics.
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Ok! I'll follow the theme. ;) with hope!
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Too bad this thread stops.
I have a question about iciss.
Why is it so expensive, why since 1994 no software can match its accuracy?
I had a demo, very impressive, you can extract colors so so easily, and so so faaast...
Is there lot of shop using it? Is there any good software that can come close to it ?
Thank you
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Mark Coudrey's separation program is and was THE separation program to use. No other sep program on the market today or previously has come close. Period.
Why the high price? For those who can afford it, the price is of little concern for what it does.
Other sep programs are very useful for the average shop and you can tweak to perfection but Coudreys has always been the best.