Author Topic: Help needed! one angle halftone printing Am i using dot on dot or flamenco?  (Read 9682 times)

Offline blue moon

  • Administrator
  • Ludicrous Speed Member
  • *****
  • Posts: 6356
for those interested in the article...

http://scholarworks.rit.edu/cgi/viewcontent.cgi?article=4813&context=theses


it should be noted article concludes that the multi-angle is superior to the staggered dot layout. Unfortunately our current conversation is about single angle and inverse dot so this study might not shed much light on the later posts.

pierre
Yes, we've won our share of awards, and yes, I've tested stuff and read the scientific papers, but ultimately take everything I say with more than just a grain of salt! So if you are looking for trouble, just do as I say or even better, do something I said years ago!


Offline Dottonedan

  • Administrator
  • Ludicrous Speed Member
  • *****
  • Posts: 5879
  • Email me at art@designsbydottone.com
The bottom is a typical approach to handling gradation blends. each separation will be different but this is the idea. Nobody should be intending to "blend" correctly using the top "flip method" unless they would really want a tint of white shirt or white base to show through. There are those occasions when you want to tint it back with white.
Artist & Sim Process separator, Co owner of The Shirt Board, Past M&R Digital tech installer for I-Image machines. Over 28 yrs in the apparel industry. Apparel sales, http://www.designsbydottone.com  e-mail art@designsbydottone.com 615-821-7850

AdvancedArtist

  • Guest
You have to start with looking at and understanding color, tint, shade and tone and how each of these color components play out in the gamut of any image/graphic you want to print. All these components have values which can be translated into ink coverage through the halftone printing process. The goal is maintaining the values in the ink coverage of the printing which in turns provides the best color simulation results. Is perfection possible from additive to subtractive color I think not as subtractive is based on reflected light and additive on generated light. However our goal is to get as close as possible.

Offline Dottonedan

  • Administrator
  • Ludicrous Speed Member
  • *****
  • Posts: 5879
  • Email me at art@designsbydottone.com
I understand color enough.  Tint for example, is not by adding black, but to add white or light.  Shade is to add black or subtract light for example.  In the few examples you've shown/written, you're showing white as if this is what we get all the time when using flemenco or single line screen and not reversed out.

You would only have white (if) you intended for white to be there. Separators and even non separators would look at an area that is to be a good orange and would determine if there should or should not be any white there so they make it so. As Pierre mentioned, there is some white in orange. So depending on the orange you are trying to represent, you add in something or take away something to make it closer.

PMS 1655 orange for example is a very good orange and is made up of 0c 63m 91y 0k so there must be some white shown. In RGB or even HSB there would need to be some white to represent that specific color correctly or as close as we can. It all depends on your target color to represent. That was CMYK but when working with only a specific red and a specific yellow, (how much) you use of those will be different.

Lets say you have a 2 color logo and basic graphic to print and the customer put in a gradation and an element that is solid orange and the print is going on Navy. (This can happen). It is now 3 colors with the white underbase.

The red in the logo is a dark red pms 193 and you have a pms 123 yellow in the logo as well. You don't want to use a 3rd color orange due to cost and quantity of say 24 shirts So we won't have 4-5 colors to mix up to help you create this nice orange more precise.  Here, in this case, you work with what you have. You would show more 123 yellow and what is a solid orange area would not have solid red over solid yellow. The darkest area in the red halftone may only be 70% to allow for more yellow to show through and print sequence can be a factor as well. Print the red over top, it's more of a rich darker orange. Print yellow over top and it's more of a yellow orange. Each example may have the halftone % applied accordingly or different. Then depending on the tint or shade of that orange, you may want some white underbase popping through or you may want some navy garment showing through.


Other things to consider to determine (how much) you use of your % of each color would be regarding the mesh counts that will be used.

You would have to approach this differently if it's going on Navy sweat shirts versus only a tee...Then you also have the question of needing a LB underbase on a much lower mesh...AND, does that white underbase have any halftone in it? Highly possible. So now your LPI may need to come down to accommodate that low mesh.

In the end, it's not totally about understanding color, but understanding all of the variables involved in each unique garment order.  Colors need, Colors available, mesh, garment color, garment type, quantity, ink type/modification print stroke speed, squeegee duro etc. needed.

This is why every sep program result for the most part still needs tweaked afterwords (for each job) differently.
Sure, on some occasions, you get lucky and can use the results straight out of the gate if you are satisfied with those results.  One fixed method is not useful in all occasions.

Inverting halftones I'm not against as long as it gets me the result I'm looking for but then again, I get the results I want with other methods.
Artist & Sim Process separator, Co owner of The Shirt Board, Past M&R Digital tech installer for I-Image machines. Over 28 yrs in the apparel industry. Apparel sales, http://www.designsbydottone.com  e-mail art@designsbydottone.com 615-821-7850

AdvancedArtist

  • Guest
A simple photographic image attached. Color, tint, shade tone. All of which can be translated into ink coverage through halftone printing. As a screen printer you have a huge advantage over DTG or device printing because you are not locked into a box of defined color/ink/pigment heads on a printing machine.
« Last Edit: January 17, 2016, 11:35:02 PM by AdvancedArtist »

AdvancedArtist

  • Guest

This is why every sep program result for the most part still needs tweaked afterwords (for each job) differently.


If you analyze these programs with say an image like the attached you will see why they fail and very clearly fail. But you would have to very clearly understand things in the world of color. Then there is the whole other side of this process, halftones, screens, emulsion, dot gain, ink pigments/colors and so on.

Offline mimosatexas

  • !!!
  • Gonzo Member
  • ******
  • Posts: 4221
  • contributor
and we're back to the same argument we always see...which has nothing to do with the original question.  Sorry to chime in, but my eyes are rolling really hard...

The answer to the original question is pretty much explained completely by pierre.  Cliffs notes: offset single angle dots will cause you a lot more issues than dot on dot specifically due to the issues that pop up with creating an accurate underbase, and in compensating for less than absolutely precise control of other variables (registration, ink opacity, dot gain, etc).  Digital color and color theory are great, but as Dan said they are one part of a complicated puzzle.

Offline Hugomartin

  • Newbie
  • *
  • Posts: 9
First of all I must say you guys are experts... And I would love to see or read anything about simple inverted dot... First time I hear about it.... But still didnt have an answer on what is the difference between dot on dot and the flamenco method... Hope somebody would would enlighten me. Thanks!!!!!

Offline blue moon

  • Administrator
  • Ludicrous Speed Member
  • *****
  • Posts: 6356
First of all I must say you guys are experts... And I would love to see or read anything about simple inverted dot... First time I hear about it.... But still didnt have an answer on what is the difference between dot on dot and the flamenco method... Hope somebody would would enlighten me. Thanks!!!!!

flamenco method is just an offset of the dot on dot method and is thus suffering from various issues discussed in this thread (and mentioned by mimosatexas).
you can read more about it here:
https://books.google.com/books?id=nRoMo3V5AEwC&pg=PA85&lpg=PA85&dq=flamenco+method+halftones&source=bl&ots=v9fdoqgTUT&sig=E_KKw9K8id8wKRG3eAuthCABXBg&hl=en&sa=X#v=onepage&q=flamenco%20method%20halftones&f=false

pierre
Yes, we've won our share of awards, and yes, I've tested stuff and read the scientific papers, but ultimately take everything I say with more than just a grain of salt! So if you are looking for trouble, just do as I say or even better, do something I said years ago!

Offline Hugomartin

  • Newbie
  • *
  • Posts: 9
First of all I must say you guys are experts... And I would love to see or read anything about simple inverted dot... First time I hear about it.... But still didnt have an answer on what is the difference between dot on dot and the flamenco method... Hope somebody would would enlighten me. Thanks!!!!!

flamenco method is just an offset of the dot on dot method and is thus suffering from various issues discussed in this thread (and mentioned by mimosatexas).
you can read more about it here:
https://books.google.com/books?id=nRoMo3V5AEwC&pg=PA85&lpg=PA85&dq=flamenco+method+halftones&source=bl&ots=v9fdoqgTUT&sig=E_KKw9K8id8wKRG3eAuthCABXBg&hl=en&sa=X#v=onepage&q=flamenco%20method%20halftones&f=false

pierre


You are the man! thats what i was looking for Thanks!

Offline Hugomartin

  • Newbie
  • *
  • Posts: 9
Now if I want to try the flamenco method how do I offset de dot in the software (photoshop)6

Offline Hugomartin

  • Newbie
  • *
  • Posts: 9
And last I might be asking too much (Sorry ;) ) but I would appreciate any reading material as posted before on the subject of printing methods... articles, threads, PDF book to share anything! And again than you You guys might have different points of you but are all cracks the same... thanks for sharing your knowledge and experience...

Offline Frog

  • Administrator
  • Ludicrous Speed Member
  • *****
  • Posts: 13952
  • Docendo discimus
And last I might be asking too much (Sorry ;) ) but I would appreciate any reading material as posted before on the subject of printing methods... articles, threads, PDF book to share anything! And again than you You guys might have different points of you but are all cracks the same... thanks for sharing your knowledge and experience...

Sounds like now you are looking for more general info on screen printing in general.
Well, here it is. Right in this very forum, just have a seat, pick a section,  and read, read, read.
That rug really tied the room together, did it not?

Offline Hugomartin

  • Newbie
  • *
  • Posts: 9
And last I might be asking too much (Sorry ;) ) but I would appreciate any reading material as posted before on the subject of printing methods... articles, threads, PDF book to share anything! And again than you You guys might have different points of you but are all cracks the same... thanks for sharing your knowledge and experience...

Sounds like now you are looking for more general info on screen printing in general.
Well, here it is. Right in this very forum, just have a seat, pick a section,  and read, read, read.

Not in general i do simulated process o lot and want to know why i do what i do and whant to get better at it... that is all about halftones and printing methods regarding halftones... My point is I have lots of questions like why or literature says 45 degree angles for dot on dot but most of the people i know including my self uses 22.5... I was hoping there was a particular source on the subject instead of reading a page with thousands of posts... Thanks for the advise anyway ill look around in the forum...

Offline blue moon

  • Administrator
  • Ludicrous Speed Member
  • *****
  • Posts: 6356
And last I might be asking too much (Sorry ;) ) but I would appreciate any reading material as posted before on the subject of printing methods... articles, threads, PDF book to share anything! And again than you You guys might have different points of you but are all cracks the same... thanks for sharing your knowledge and experience...

Sounds like now you are looking for more general info on screen printing in general.
Well, here it is. Right in this very forum, just have a seat, pick a section,  and read, read, read.

Not in general i do simulated process o lot and want to know why i do what i do and whant to get better at it... that is all about halftones and printing methods regarding halftones... My point is I have lots of questions like why or literature says 45 degree angles for dot on dot but most of the people i know including my self uses 22.5... I was hoping there was a particular source on the subject instead of reading a page with thousands of posts... Thanks for the advise anyway ill look around in the forum...

post specific questions and you'll get specific answers. Most of us don't have the time to write a book. Also, conisder taking classes at the ISS shows. I am teaching two mid to high level classes this year (one on business development and another on screenprinting variables).

45 degree works on paper in the industries that don't use screens. Printing 45 degrees on the mesh hits the knuckles and causes pretty bad pattern interference (moire). By going to 22.5 you are skipping the knuckles and going between them (as much as that's possible).

pierre
Yes, we've won our share of awards, and yes, I've tested stuff and read the scientific papers, but ultimately take everything I say with more than just a grain of salt! So if you are looking for trouble, just do as I say or even better, do something I said years ago!