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Computers and Software => RIPs => Topic started by: Gilligan on November 25, 2014, 07:51:14 PM
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Example, you print a halftone under base and follow up with a top color. Then the top color needs to sit RIGHT on top of the underbase dots.
BUT, if you want to make say green (just for easy to follow example), you want to have Yellow lay NEXT to Blue to make it "look" like green from a distance.
First example is 50% pink with a 50% underbase on say a black shirt. Second example would be 50% yellow and 50% blue on a white shirt. RIP doesn't know what colors or what.
Maybe I'm completely mistaken on how this would work out, so please enlighten me.
I was thinking of a different way to work some art we printed the other day, just for future purposes sake, and it crossed my mind.
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Interlocking halftones. Send Jeff, The FullSpectrumSeparator, a message. He knows that stuff. He`s done a few seps for us with perfectly interlocking halftones. Looks so good.
Here is a link to a similar question on a different forum where he answered.
http://www.t-shirtforums.com/graphics-design-help/t206497.html (http://www.t-shirtforums.com/graphics-design-help/t206497.html)
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all the dots are on top of each other. The field of dots is set by the lpi and angle and the RIP just calculates how big to make the dot in each position. In some places it will be 0% and in others it will 100%.
When blending blue and yellow to make green they should print on top of each other and mix (just like you would make a green color by mixing blue and yellow).
In 4CP, the dots are printed in a rosette and rather (also a fixed pattern) and rather than physically mixing the inks, it is their proximity that gives the illusion of the green.
pierre
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Interesting Rockers, thanks!
Pierre, in that link that Rockers posted, it mentions the net result... it would be a negative space of 50% (assuming I'm printing in a vacuum ;) ). So I'd have to change to some other percentage to achieve what I wanted.
Do any RIPS do this automagically?
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Interesting Rockers, thanks!
Pierre, in that link that Rockers posted, it mentions the net result... it would be a negative space of 50% (assuming I'm printing in a vacuum ;) ). So I'd have to change to some other percentage to achieve what I wanted.
Do any RIPS do this automagically?
Jeff told me the new version of Simple Seps raster comes with an interlock halftones feature. Should be available via his website.
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Interesting Rockers, thanks!
Pierre, in that link that Rockers posted, it mentions the net result... it would be a negative space of 50% (assuming I'm printing in a vacuum ;) ). So I'd have to change to some other percentage to achieve what I wanted.
Do any RIPS do this automagically?
nah, good idea, but not really usable for several reasons. . .
pierre
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back in the old days -- i used to setup my screens to interlock -seemed to make sense.
although i haven't in years, since the advent of computers and rips.
Pierre, please explain the reasons ...
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There seems to be a difference of understanding in what makes a green from blue and yellow.
As Giligan has defined by placing the dot side by side, that's not truly mixing. That can be done, but in that case, it's the eye,size of libe count, and your eye that blends. An example would be indexing. That is putting dots side by side using square dots. The higher the Rez, the smaller the dot. The smaller the dot,?the higher the mesh needed and also the lighter the ink is put down.
Stochastic dots are also square but are treated like traditional sim process where the colors and dots run under each other to "blend" or mix. This is what you want to do with traditional halftones to achieve the best color blends as Pierre had indicated.
Vector programs by nature, knock out of each other and place space and dots butt up against each other.
If you want to blend colors in vector, make a colpy of your blend and past undernieth. Then extend the yellow fade out further. Tell that yellow to overprint. Then tell the top copy to also overprint. Simple blends will come our better.
In photoshop, sepping manually, you do this yourself. This is another reason that ps seps are used often over vector. Sure, it can be done, but it's raster in photoshop.
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Dan, since you have so much time on your hands these days. ;) ;) ;)
Would you be able to throw together a quick sample of what you are talking about? Just big ugly blocks would be adequate for me to understand an do some R&D with.
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When blending blue and yellow to make green they should print on top of each other and mix (just like you would make a green color by mixing blue and yellow).
In 4CP, the dots are printed in a rosette and rather (also a fixed pattern) and rather than physically mixing the inks, it is their proximity that gives the illusion of the green.
pierre
The most accurate way for 4-color process is actually to overprint all CMY dots the same angle except invert-lock the black with the other colors.
The most accurate way for plastisol/opaque inks to blend is Interlocking all dots, index/stochastic FM or halftone AM.
It is called the scientific method, it is a wonderful thing for having a question about the physical world and then running experiments and tests and comparisons to draw conclusions that are accurate and reliable.
People can share their opinions based upon their apparent lack of understanding of these subjects, but it doesn't help the actual scientific progress going on, and it gets taken as fact by otherwise uninformed readers, which can actually harm the progress of the industry.
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Jeff, I think that you at least owe Dan a thank you for the fuel for you to heat up this discussion! I understand that you're looking at some cold temps up there! ;)
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Jeff, I think that you at least owe Dan a thank you for the fuel for you to heat up this discussion! I understand that you're looking at some cold temps up there! ;)
Lol... I was restraining myself for a while with this one, but you're right now I've gone and lit the fuse. :P
https://www.youtube.com/watch?v=wmin5WkOuPw (https://www.youtube.com/watch?v=wmin5WkOuPw)
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I went ahead and removed Jeff's post due to name calling. As mentioned before, we will not tolerate those.
Pierre
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Why not just clean it up and leave it posted?
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When blending blue and yellow to make green they should print on top of each other and mix (just like you would make a green color by mixing blue and yellow).
In 4CP, the dots are printed in a rosette and rather (also a fixed pattern) and rather than physically mixing the inks, it is their proximity that gives the illusion of the green.
pierre
The most accurate way for 4-color process is actually to overprint all CMY dots the same angle except invert-lock the black with the other colors.
The most accurate way for plastisol/opaque inks to blend is Interlocking all dots, index/stochastic FM or halftone AM.
It is called the scientific method, it is a wonderful thing for having a question about the physical world and then running experiments and tests and comparisons to draw conclusions that are accurate and reliable.
People can share their opinions based upon their apparent lack of understanding of these subjects, but it doesn't help the actual scientific progress going on, and it gets taken as fact by otherwise uninformed readers, which can actually harm the progress of the industry.
I might not have explained it very well, but the question was about the RIP and the dot placement not color theory. So an easier to understand answer would have been to say that if the lpi and frequency are the same, all the dots will print on top of each other (physically blending the ink). If one or both are different, it will create a pattern. Further more, If the lpi is the same the dots can be printed next to each other and will create an evenly repeating (non moire) pattern that our eye will see as the blended color (this used in the printing industry other than garments to produce the 4CP prints).
These are facts and as long as your RIP is working properly any scientific testing will confirm it. So pleas do not take my answers out of context and twist them into something else.
Pierre
P.s. This pertains to the halftone dote that are amplitude modulated as they are the predominant type used in screenprinting
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Why not just clean it up and leave it posted?
Because it is not my job to go cleanup Jeff's answers every time he starts something. Even more so when his answers are not addressing the original question. He is more than welcome to start a new topic discussing color theory and half tone printing. If I have the time, I would like to participate in that conversation as Jeff often has very good information worth listening to, but there are also often ideas that are not practical to implement in the real world. This is what makes for a good conversation (as long as it's civilized and everybody is willing to listen to each other).
Pierre
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Why not just clean it up and leave it posted?
Because it is not my job to go cleanup Jeff's answers every time he starts something. Even more so when his answers are not addressing the original question. He is more than welcome to start a new topic discussing color theory and half tone printing. If I have the time, I would like to participate in that conversation as Jeff often has very good information worth listening to, but there are also often ideas that are not practical to implement in the real world. This is what makes for a good conversation (as long as it's civilized and everybody is willing to listen to each other).
Pierre
Your comment: "but there are also often ideas that are not practical to implement in the real world."
This is just ridiculous.
I am an artist, color separator, and work as a SCREENPRINTER at a small print shop, I take things from start to finish - IN THE REAL WORLD.
I have been implementing my ideas in graphics and printing for over 14 years, at digital, off-set, large format, and screenprinting shops.... in the real world.
You are way out of your league Pierre. Your statements continue to act like science, but are unfounded and untrue. They are easily proven to be inaccurate in terminology for one, and false when put up against the rule of science - which involves implementing and testing and comparing things accurately in the real world.
It is not my job to correct your false statements which butcher the very definition of science.
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Science schmience. It's a tee shirt and we are printers. I delved into the "science" of it briefly, if one can even call it that, and it's a financial time waster. I had to ask myself, is all of this really worth it in the end or am I just putting time and the Co's money into something to make myself feel like an important scientist with no real documented ROI for the shop owner worth mentioning? Has the benefits increased my sales by 2%-5%-50% or any at all?
Outside of or above the basics, the answer would be, not much unless you go all out to maintain complete control and awareness of all variables all the time, purchase the right equipment and posses the right knowledge to do so. The "science" you call it, is not that beneficial financially, It's great if you personally desire to know all you can and have all the equipment that you can to achieve this as well as to having the type of or all of your customer base requires producing museum quality prints. Guess what? Even museums sell sub par souvie tees due to price.
Put a halftone down, make a halftone "work" to where it looks good, get your orders in and out on time, and keep cost down, then go get more sales. I think that should be most peoples focus.
For me, my focus for 2015 will be to really drive home the need for mastering "the basics" on a larger scale than I have been. We tend to consider ourselves (this forum) the more experienced and while that is true, there are many who still are not applying some of the fundamentals of printing. I still believe we have much to learn and can even benefit if we can somehow illustrate the basics better so that people are more able to understand and more willing to put it into action. Once they can buy into something, by believing in what they see and read, they are more prone to put this into action. Therefore, I think some interactive print files "test files" should be available for our members to practice with and can be discussed either out in the open or in private by email and phone.
The Science part is good to know for some and certainly can boost can ego but thats about where it stops for me. I feel I've learned enough to know I don't need to learn it all and I know what is not necessary for me to focus my attention on. Devoting some time to "the science" helps one reach father than they may have come had they not sought out more. I feel tho, for myself, The time, energy and money spent on gadgets and the search is not as beneficial as one might think. Thats not to say that someone can't reach close to perfection. Reach for the stars and you can get off the ground.
Edited as a result of my fast fat fingers for spelling as well as elaboration.
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[/quote]
I am an artist, color separator, and work as a SCREENPRINTER at a small print shop, I take things from start to finish - IN THE REAL WORLD.
I have been implementing my ideas in graphics and printing for over 14 years, at digital, off-set, large format, and screenprinting shops.... in the real world.
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Can you post some of your artwork and printed shirt examples showing your design ability and print quality. Your delivery makes it sound as if your work is scientifically perfect. Some actual photos of artwork with print comparisons side by side would be nice to see.
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Why not just clean it up and leave it posted?
Because it is not my job to go cleanup Jeff's answers every time he starts something. Even more so when his answers are not addressing the original question. He is more than welcome to start a new topic discussing color theory and half tone printing. If I have the time, I would like to participate in that conversation as Jeff often has very good information worth listening to, but there are also often ideas that are not practical to implement in the real world. This is what makes for a good conversation (as long as it's civilized and everybody is willing to listen to each other).
Pierre
Your comment: "but there are also often ideas that are not practical to implement in the real world."
This is just ridiculous.
I am an artist, color separator, and work as a SCREENPRINTER at a small print shop, I take things from start to finish - IN THE REAL WORLD.
I have been implementing my ideas in graphics and printing for over 14 years, at digital, off-set, large format, and screenprinting shops.... in the real world.
You are way out of your league Pierre. Your statements continue to act like science, but are unfounded and untrue. They are easily proven to be inaccurate in terminology for one, and false when put up against the rule of science - which involves implementing and testing and comparing things accurately in the real world.
It is not my job to correct your false statements which butcher the very definition of science.
I stand corrected, I keep thinking from my shop's perspective and what I deem acceptable is different from what others do. It is possible that shops with higher or lower standards might be able to use some of your ideas, but I don't see some of them working for us.
as far as science, I am finally pretty comfortable saying I know what is it that I don't know. I am still out of my depth with ppl like Coudray, Clarke and Greaves, but know a lot more than you would imagine. I think you can count on fingers of one hand the number of shops in USA that have a spectrometer, densitometer (transmittive and reflective), EOM meter, durometer meter, UV meters, microscopes (yes, multiples) and a viscometer amongst other tools. We have won several SGIA golden image awards and handful of ISS awards (amongst others). Several manufacturers trust us to test their product prior to release and one major ink manufacturer changed their QC process as a consequence of having a conversation with us. Couple that with my computer engineering schooling and I am pretty comfortable in BELIEVING in my science. If there is something that I am saying is wrong and you are willing to share, please do, but do it in a different (new) thread. feel free to call me out in public as I don't have anything to hide (the only reason I am not as active is because I am busy, not because I am avoiding or hiding).
pierre
p.s. Most of the above is not for the purpose of bragging. It is to validate where my opinions are coming from. This does not make me right all the time, but statistically I am significantly more likely to be right than wrong. For anybody still with me at this point, I suggest checking out this link http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect (http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect). It will explain why one of the most knowledgeable members here (Dave from Bimmridder) is questioning everything and some others are posting "the truth".
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I can appreciate your definition use of the word scientific. The passion and the enlightening moments can make it feel this way. Let's say that I would be "out of your league" and you were truly beyond me ten fold, what you and I do and your distance between us still does not make us scientist. It makes your level of understanding of the affects of using one thing over another, better than the other.
With your knowledge, you can sell products that include sep programs, and the like. That's a great thing for you. Instructional tutorials would be a good avenue for you to take. Something that provides you an oppertunity to get your information out there using (one way communication). Bickering and name calling and the desire to prove people wrong or to damage someone whom you don't agree with is not useful to anyone, nor does it represent your knowledge well.
I'll bet your're a good person. I'll also bet that you would be a good father, husband or grandfather. I'll also wager you could increase your life span if you could only control yourself as well as you do Screenprinting. you may be much happier and probably may increase sales just a little. Shoving a self proclaimed "science" down someone's throat is kind of like having religion shoved down someone's throat. It doesn't matter if your intensions are good or if you are right or wrong, the message would be delivered wrong and not received.
Once you realize we are not here to bicker, or outright dispute what you say, this becomes a valuable, friendly place for you. We are here to learn, discuss our daily issues, increase sales, rant about customers, and gain knowledge we might not have had before, we live a happier life and invite wisdom with open arms then you gain trust, respect and appreciation.
Most of the juice in this thread is now about you, me and Pierre. Let's go back and look at the question.
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I read Jeff's long post before it was deleted, and it was in line with his standard posts: throw out a bunch of terminology, act superior, fail at actually arguing his point, and make everyone yawn. I am a relative newbie compared to a bunch of the folks on this forum, but even I can see through the bullshit. I second Danny's call to actually see ANY concrete evidence that understand color theory and some terminology has translated into producing perfect prints. There are so many variables beyond how something looks and acts in adobe/corel that affect the quality of a final print. It gets seriously old seeing the same "I'm a self-proclaimed digital color theory genius so everyone knows nothing about screenprinting" drivel...
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I decided to check into using the two different screen angles as Jeff from Full Spectrum Separations had indicated. For a long time, I had veered away from using multiple screen angles (on screen printing) for various reasons. One for example, is that I have read over the years from previous and current guru's that the use of various or multiple screen angles in the same design is not needed (on apparel) due to the lack of image resolution typically used on apparel. Where you may find the use of multiple angles quite often is in the offset industry for example. Perhaps that may be where Jeff found his love for the multiple angles. Offset uses higher line counts and is able to allow you (the viewer) to use your eyes to blend any imperfections in print more so than screen printing allows for, due to the higher line counts for them, (e.g) 100 lpi and above. Screen printers typically use lower line counts (e.g.) 45, 55 and 65lpi are not often able to benefit from using the multiple angles as much.
One of the benefits of multiple angles are to assist in improving image detail and color tone but they come with some visually interfering "patterns side affects" as a result. At lower line counts, these are more visible and can be a nuisance. There may be additional benefits than image detail in shadow tones and highlights that I'm not aware of but thats about the gist of it.
Below, is an example of some comparisons. They are not intended to dispute the use of multiple angles, but simply to show what happens with each and to assist you in making your own choices for use. In the first image, I cropped a grayscale separation file and ripped it at 55lpi assigning 22.5 on the pms 312 blue/teal and 67.5 to the pms 122 yellow.
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My cousin is an offset guy and occasionally helps me out in my shop. We tested the standard offset angles for cmyk screenprinting with 45 and 55 lpi with both clear centered and dot centered rosettes on a small cmyk test run for a brand I print for. Literally the first words out of the customers mouth when he picked up his shirts were about the visible rosette pattern.
Dan is pretty much dead on. Rosettes are great for offset printing with huge lpi because the pattern is not very visible and at offset tolerances on flatstock they reduce visible color shifts. On a shirt using much lower lpi the rosettes become much more visible AND as a result they do not offer the advantages they would in offset printing, or rather the cons outweigh the pros. Using single angles allows much better print resolution/detail AND reduces moire due to slight registration issues at the much lower lpi, at the cost of perfect color accuracy.
This is a consensus "opinion" based on real world testing that you can read about in dozens of articles with proof and see for yourself in your shop with a few hours of testing.
edit: fixed a brainfart.