Full Color, 4 Color, 6 Color, Seps, halftones oh my!
Ok, been reading and viewing screen printing articles here and on the net as well as looking at tshirts at lots of stores...
I have been using desktop publishing software for awhile so I think I can get that side worked out.
Here is the real deal... I see alot of tshirts that look like full color prints with real gradients, and they feel like screen printed ink.
I know there are ways to get a process print accomplished using halftones and the right mix of cmyk all applied in a magical order.
Before i purchase equipment or make some other bad decision I want the straight dope.
I know how to design for 4 or 6 colors with each color separated out on a different layer so i can print each individually. And, I see a lot of single color designs as well.
It must be very hard to get true full color, what up with that.
Anyone getting good results with full color, or is there some other magic i dont possess yet.
Im yet to see a good break down on this from creation of a very colorfull design to reproducing that on a shirt?
here is one method that will help you a bit. t-shirt designs index color separation
Simulated process separations takes a while to learn. I still learn something every day and have been manually separating higher end multi colored designs for about 9+ years now
i am also having problems doing process printing.
previously i have managed to do 4-5 colour screens like single spot colours but when i recently tried process colours , it seems like a whole different dish all together.
weird (third colours) came out, single cmy colours showed through when my graphic didn't have those colours, moire patterns showing. its crazy. i went to my screenprint supply shop and they told me that i had to do trial and error for the image to appear, mixing the colours.
he told me that cos one of my test prints the grey tone turned out to be too cyan, he said replace it with grey process paint. does it work this way?!
(in this case i was trying to create the colour grey with process waterbased paint and at 40 dpi using a 48t mesh, instead it came out all colourful with yellow showing, purple as wel as cyan... )
could it be a misregistration problem such that i have to align DOT FOR DOT, such that the paints will magically create the colour, and any misalignment will "rainbow" the image.
i read a little about GCR (grey component replacement ) but that was for desktop publishing , does it work for screen printing?
process printing is really tough. There are tons of colors that are impossible to achieve with cmyk. Red and grays are big ones as mentioned grays look more blue. In order to achieve these colors you either need to run hex seps or add spot bump plates to get those colors. Your software should have an out of color gamut view to show you the areas of the image that will be hard if impossible to achieve with cmyk. This is one reason simulated process came about. You also get a more vibrant and accurate print as your using specific colors in the design rather than using 4 to create all the colors
Impressions magazine has had numerous articles on this process. You might search their site for past articles or even get reprints.
I consider myself an expert at full color printing. It is actually very easy once you get it down. The only two aspects; will you be printing on white, natural, ash or on "darks"? And you have to have some experience with Photoshop and its quirks and be able to imagine what is going to happen at the press. I try to get as much detail in the black screen as possible; that way I can flash all the previous colors once, print the black and BAM! nice crispy detail and you don't have to futz with the job while it is running.
I goofed around with Scott F's FastFilms, and from that 20 day trial they offer, I got a pretty good idea on what to do; especially when it comes to simulated process. Now, I just do it all myself because I have total control over the outcome, but its a good place to start. You had mentioned that you print from layers. You have to learn how to adjust and print from channels. There you can even mix channels to see what it will look like and maybe eliminate a screen or two when you are doing simulated process.
What I use after I make the seps with 65 lpi eliptical dots and all the right matrix angles, are tight 305 mesh screens (yellow), coated one outside/one inside dried printside down in a humidity controlled environment with lots of air movement. I use SaatiChem PV textile emulsion. I use a poly-cop with a 5000 watt metal halide gas bulb and shoot for 18 seconds. I consistantly get 5% dots to washout and no pinholes. After the screen has been dried and prepped I reshoot it for about a minute to harden it.
At the press almost any prebased-out Process ink will work. Squeegy angle and pressure and flood pressure is critical as well as off contact. That you have to figure on the fly. Everything has to be square and level.
For darks its about the same but you have to goof around with opaque colors that simulate process. Also, in Photoshop you will have to pull out 2 spot colors. One for a basewhite and one for a highlight white. You rarely have to flash.
What I tell my customers also (since we are in a digital age) is that we are not printing on white paper. I show them a kick-butt piece I have done previously. They are blown away and then I tell them the object is not to have the colors exact but have the print stand on its own. That way there are no surprises and you will be extremely close anyway if you do it right.
Wow Dale, Thanks for chiming in!
I am familiar with channels and know how it SHOULD work.
Are you saying that you print tshirts the same way I would print a four color process magazine ad? You are creating CMYK seps from channels... halftoned to 65 lpi eleptical then you shoot your screens. What color order?
I have never done this process personally, I am the guy dropping off the artwork to be printed, i build in cmyk and my printers take care of everything else. So im just trying to get a good grasp of not only if you can achieve consistent results with process printing to tshirts but also some separation and screen set up basics as well.
Process printing is not that easy. It isn't that hard yet takes some skills and good equipment. I have been printing and separating high end designs for 11+ years and learn new thing with every job. The issue with -clr process is that most people think that a full color design is a 4-clr process and that is usually not the case.
4-clr process has its pros and cons and for the most part I would say the cons outweigh the pros. (mainly the learning curve on the art & prepress end)
Yeah 4 color process is not the be all and end all for sure fluid. And you are right full color does take bump colors and all the rest. It's still not a chore though; once you understand the whole picture.
I've had to determine the sequence of print on a per job basis. Usually the dark colors print last BUT some of the highlight colors Greens, Yellows, and orange show up better toward the end of the print sequence. i just finished a job with six simulated process colors on a white shirt for a local Mexican restaurant and had to adjust the print color sequence. I printed all six colors wet- on wet.
I also found that by manually floodinmg the screen first and then PUSHING rather than pulling the squeegee across the screen gave better color saturation. I understand there are push squeegees available and I might try them in the future.
It's a lot of stroking for a manual press. Oh for an automatic.
I've had to determine the sequence of print on a per job basis.
This is definently the case with most if not all spot color designs.
With CMYK the normal method is Y,M,C,K yet sometimes the order needs to be changed
A general rule is lightest to darkest and smallest print area to the largest yet these do not always work depending on the design at hand and whether you are mixing on press which will usually color dictate for proper
mixing
I am really sorry (not) but I stopped goofing around with the color order back in the 80's. If you do it right it will print "ymck"
Yes if you do it right. again this takes time and we are talking with newbies who don't know what to look for in the channel seps before priting films and burning screens
Full Color, 4 Color, 6 Color, Seps, halftones oh my! 
