# 4 color process help



## brich (Aug 12, 2008)

I have experience printing 4 color process lithographically, but not with screen printing. I am working with some people who have been screen printing for over 20 years, but have not done any process color work. We got a t-shirt press and we can print spot colors and tints without a problem, but now we are getting orders for process color shirts and unfortunately we have to turn them away to other printers. I printed my first test image and wanted to get some feedback. First let me say that I did check through the forum before printing and got some good help. Here is my current process: I entered the spectral data for my inks into photoshop and separated my RGB file into CMYK. Most of the incoming orders are for dark shirts so I skipped printing on white and went straight to black (too ambitious?). I manipulated the separations to subtract out the black (using the shirt instead) and create a white channel. The channels were then sent to film at 65lpi eliptical and burned on 305 mesh screens. The press is an M&R rotary 8 color. I was told to print white, flash, then print wet on wet yellow, magenta, and cyan in that order... correct??? The image looks more like a faded painting than a photograph. Follow the links bellow to see the print. The first link shows the original artwork. The second image compares the original artwork and the separations/dots as they should have appeared and the actual print. The third link is to a picture of the entire print. The dots seem smeared and although I was able to get dots in the highlights, they lack detail. Also, can anyone recomend any software or techniques for making a white separation for process printing on black or dark garments? I tried using fast films, but I could tell that the white channel was just not correct so I didn't bother to print it. Am I using it wrong? A salesman just recommended using the Wasatch SP RIP, but I looked into it and can't find anything saying that it supports these dark garment separations. Any help would be appreciated. 

Tree on Flickr - Photo Sharing!
Comparison on Flickr - Photo Sharing!
Scan_of_Shirt on Flickr - Photo Sharing!


----------



## Roboto (Apr 6, 2007)

You should try simulated process on darks


----------



## brich (Aug 12, 2008)

what software do you recomend for it? I have been trying FastFilms, but have had better results doing the seps myself.


----------



## RichardGreaves (Nov 7, 2006)

You can download and use free trials of FastFILMS and Spot Process. Both can do the dozens of steps required to separate for dark garments and make an underbase automaticly. Yes, the more you use it, the more you see what it does and you will learn how to tweek your original art so the finished product comes out fantastic.

FastFILMS -20 days and can create 7 different types of separations including CMYK
U.S. Screen Print & Inkjet Technology | FastFilms

Spot Process -30 days separating any 2500 pixel .TIF file into 8 unique colors in 30 seconds
Software For Screen Printers - Color Separation Software

I can use either one and have the separations made in less than 10 minutes. Of course, it then takes me 20 minutes to add all the center lines, registration marks and ink color labels etc.


----------



## fdsales (Jul 1, 2007)

Printing process color on a manual press, especially on white base, is very difficult. Your squeegee pressure & squeegee angle play a very important role in how the final print appears. It might be more your printing technique, rather than the seps themselves. Since it's impossible to constantly control both pressure & angle on each stroke, you will get prints that will vary slightly in appearance. Too much pressure tends to send too much ink thru the mesh. To low a squeegee angle also deposits too much ink.


----------



## out da box (May 1, 2007)

Hey Brian do you have a sample of 4color process on dark w/underbase that you can post? I really need to see some samples of this pulled off well.


----------



## out da box (May 1, 2007)

I always use simulated process on darks. Here's a 6 color mock-up of what the pic may look like printed.


----------



## brich (Aug 12, 2008)

Thanks for all of the responses. I used Wilflex Low Bleed White for my white base (I typically have to print on flourescent polyester so this is my standard). The underbase was printed and then flashed, the other colors were printed wet on wet. The cyan, magenta, and yellow were the standard wilflex process inks. These three inks were diluted with softhand clear in the following amounts: cyan (75%ink/25%softhand), magenta (65%ink/35%softhand), yellow (83%ink/17%softhand). The percentages are measured by weight, not volume. I am working on a new set of simulated process separations using SpotProcess with 6 inks. We have a lot of orders coming through so I don't get much press time for testing but I will post more as soon as I can get them done.

Out da Box - thanks for making that 6 color preview. What software did you use to make the separations?


----------



## out da box (May 1, 2007)

Photoshop- ALWAYS.


----------



## brich (Aug 12, 2008)

I have tried making simulated process separations in photoshop with little success. Here is the method I used: Put the image in index mode using 6 colors (inks I have) - then separate out the 6 different colors and then blur the "squares" created by the index mode to make it into a more continuous tone. Then I send them to the RIP to make eliptical halftones 50 lpi and all colors at 61 degrees. I have never heard of anyone doing it this way... just an idea I had. Is there a standard method? For now I am still figuring out SpotProcess.


----------



## out da box (May 1, 2007)

Never "blur" anything using index. Simulated process is different than index. 
Basically the technique uses channels exclusively. Underbase plates, and top color plates, as well as highlight plates are sperarated out of the artwork and saved as channels. The channels are converted to "spot" colors and then outputted to a RIP to print to an inkjet or laser or imagesetter. The channels are all greyscale components of a design.


----------



## brich (Aug 12, 2008)

How do you actually select the colors to go into the individual channels? Do you use the picker tool and then paste the selections in the channels? Thanks for the help - I really do appreciate your effort.


----------



## out da box (May 1, 2007)

Select color range, then save as channel, then convert to spot color. The process takes practice, but that's how it's done. Picking the colors is the tricky part, and then adjusting individual channels with the curves tool to get what you want. The underbase is the most important channel.


----------



## antman428 (Sep 1, 2007)

I just purchased Quikseps from QuikSeps Simulated Process Color Separations.
It is the best thing I have come across for the money.
If you contact the company directly through email he will give you his ebay price of $156 w/shipping, you can't beat that. There is also a 15 day trial. I can't believe I've been doing separations for so long without a tool like this. I tried Fast Films also and it just doesn't get you where you want to be. It takes you about 70% of the way. Quikseps will get you all the way almost every time. You may still need to tweak some channels for more complicated things.


----------



## out da box (May 1, 2007)

Quickseps, easy art, fast films are all good if you're doing simulated process separations. You've gotta still tweak, but man it sure does save time.


----------



## antman428 (Sep 1, 2007)

That is the truth, man if I could have all that time back from when I didn't use it...


----------



## out da box (May 1, 2007)

Fred, that underbase process looks good, I've got to experiment with that soon. Simulated uses standard opaque colors. I uasually use the same 5 or 6 colors. They are not transparent and do not need to be mixed. They are printed with halftones and the halftone patterns can allow for color mixing rendering different shades/hues.


----------



## brich (Aug 12, 2008)

Fred - yes the inks are plastisol, and the softhand was added because the manufacturer stated that it was necessary (and even provided the percentages). It goes without saying that the inks are transparent after diluting them. I think that they would be fairly transparent even before the dilution despite the claims by Wilflex that they are "condensed pigment load inks". Do you or anyone else have any process inks that you recommend? I am open to try new things.


----------



## out da box (May 1, 2007)

This is a job we just finished using the simulated process technique, this one was 3 colors- underbase white, red, highlight white. Used 65lpi screens on 230 and 355 mesh. Wilflex standard plastisol inks. That dang udc-2 emulsion is ultra for detail!


----------



## Smokestack (Aug 4, 2008)

i use spot process(the stand alone version. not the photoshop plugin) I absolutely love it. There is always a bit of tweaking involved but one of the beauties of spot process is you can load textile values (gildan, hanes, etc) and also ink values(wilflex, rutland). I used to do my simulated process painstakingly by hand in photoshop but since i got spot process a few years back. Its all i will ever use


----------



## jgabby (Mar 29, 2007)

HI,

Fred, do you halftone your underbase ?

THks


----------



## out da box (May 1, 2007)

Fred, I played with some "plasticharge" white a few months ago, didn't work well at all. Maybe I didn't do something right. Let us know how you make out with it.


----------



## brich (Aug 12, 2008)

I took a look at my dots and they look fine - nice clean edges. Proccess printing is not new to me, but screen printing is new to me so I don't know much about emulsion. Our company has always printed membrane switchboards, nameplates, control panels, ect. So, right now I am using Kiwocol Polyplus S emulsion, but I saw that Ridgely recommended udc-2 emulsion so I will try to track some of that down. At first I thought that the problem was my separations, but now after seeing what everyone has to say here, I can tell that I need to make sure that we are able to consistently print halftones before I can attempt separations. I am downloading some sample separations to test.


----------



## brich (Aug 12, 2008)

Fred - I have printed a test target... (ECI2002) and had good results with it (only printing on white cotton though - I didn't attempt it on an underbase yet). I can mail it to a friend who can then make me an ICC color profile... do you or have you ever used an ICC profile for screen printing and if so, is it reliable and do you recomend a certain target?


----------



## Locklear (Nov 24, 2006)

I also have recently started using Quickseps, and so far I like it.

Here are a few pics from a 4-color process job I recently did. The separations were directly output from Illustrator using FastRIP.


----------



## brich (Aug 12, 2008)

fred - When you say "normalization of the transfer curve" - are you simply linearizing the press or are you adjusting the curve to produce neutral graybalance. In other words, are you adjusting to make C50, M50, Y50 a neutral gray or are you only focusing on making a 50% tint print as a 50% tint and just relying on the accuracy of the pigments to balance the color?


----------



## brich (Aug 12, 2008)

does anyone know of any classes or seminars specifically for process color/simulated process color printing of t-shirts. I know that SGIA has something but the next class is in a year.


----------

