Screen Printing HSB and Color Separations

[blue moon]

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

[AdvancedArtist]

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! 

[mk162]

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.

[Dottonedan]

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.

[AdvancedArtist]

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.

[Dottonedan]

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.

[AdvancedArtist]

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..

[blue moon]

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

[blue moon]

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

[AdvancedArtist]

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.

[blue moon]

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

[AdvancedArtist]

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.

[drdot]

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. 

[tonypep]

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.

[AdvancedArtist]

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.