Hi. I am getting ready to screenprint a cmyk image onto a white t-shirt. I have done the following things using X3: Taken my image and converted it to cmyk bitmap, changed bitmap into halftones, separated the four colors and laser printed them in black onto my film. I am getting ready to expose the art onto 195 mesh screens and see no problem there as I have been able to get good exposure on them in the past even with the smallest halftone dots. Here's my problem: Looking at the artwork, some of the 4 colors overlap quite a bit where there is a solid image. For instance there is to be a brown area in the print and c,m,and y look like they're right on top of one another. So when I'm getting ready to print this image do I flash between colors or just go wet on wet hoping that it will blend on the shirt? Have I done something wrong with separating the colors? Thanks!
Here's my problem: Looking at the artwork, some of the 4 colors overlap quite a bit where there is a solid image. For instance there is to be a brown area in the print and c,m,and y look like they're right on top of one another.
Swilbert-
process printing involves many variables that need to be exactly calculated to get a constant. (consistent, perfect print.)
i don't know much about it, other than what i have read, but a few things to possibly focus on:
proper screen angles. (may need to test from adobe default levels.)
halftone dot shape at oval, and around 55 lpi on a 305 mesh.
hard squeegie, properly tensioned mesh.
tight registration on press.
print wet on wet and play with your print order.
using spot colors to achieve accents, particularly reds.
I pretty much know you're not going to have great results with 195 mesh count. You need 305 and in some cases higher.
Also, like derek said. Hard squeege is key, but so is EXACTLY tensioned screens that are all the same. You're going to need to have the same pressure on each screen because you need to make sure the ink is evenly distributed, or else you'll have weird looking shirts.
You'll have to play with the angle, but be prepared to eat a few shirts before you figure out the angle and pressure on the screens.
Go wet on wet between colors and unless you're seps are at 35 dpi, you're going to need a higher mesh screen.
BTW, the screen angle of your seps is exteremly important so they don't create moire patterns between each other, but also with the screen mesh. When I do sep, I set ALL colors to 70 degrees. I know it sounds strange, but this is the combination that has worked for me for the past 15 years. Once I figured it out, I kept running with it and it's worked fine every time. Try it if you like, there are many angles that will work, this worked for me.
Don't forget to take into consideration dot gain when creating your seps...
Are my results going to turn out bad because of the amount of ink going through a 195? Beacause I have exposed the screens and they turned out good as far as I can tell.
Are my results going to turn out bad because of the amount of ink going through a 195? Beacause I have exposed the screens and they turned out good as far as I can tell.
because the mesh has to hold the halftone dot. what lpi are you using?
as you can see, a 305 mesh has more crosslinks than a 195, thus will hold the edge definition of the smaller halftone dot.
if you are using larger dots, a 195 mesh may be sufficient, but as you get into process printing, smaller dots are required, and so, also a finer mesh.
You can try spot drying between colors if you like, but transparent inks need to "mix" when printed to create secondary colors, etc. so wet on wet usually works best.
Another trick to keep in mind is the order you lay colors down. When working with process printing on apparel, I've found that if your print is coming out too blue, for instance, print the cyan first, then magenta, yellow, blk and that will reduce the appearance of blue in the overall print. In other words, changing the print order of the inks can save you from having to do the seps all over again.
All of this has been really helpful, thanks! I printed the 4 color today with what I had available: close but not exact process colors and 195 mesh. The print turned out surprisingly better than I expected! I have since ordered some 305 and the tru tone colors as to get better results next time. I was next going to ask about the color order. I just went light to dark y,m,c,k. The last reply suggested printing cyan first which makes sense after looking at my print. Any more suggestions on color order?
Also, some areas looked darker than they should have been but when I lightened my pressure, the print was dull in color but well blended. Any help here? Thanks!
1 more thing: If i am printing 4 color process of a black garment should I underbase every dot with white or just lay a solid pallete of white under the design?
Well, I'm not a screen printer, but I've done many separations for process printing and worked side by side with screen printers to work out the print issues.
From what I've learned, you should keep your pressure as consistent as you can and adjust your seps to change lightness/darkness values. Otherwise you get exactly what happened to you, one thing gets better but something else suffers. Typical print order is from light to dark. What I was saying before is an option if the print is coming out with too much of any given color. It may save you from having to have to run the seps over again. Just something to try before throwing out your screens and starting over if the print doesn't come out right.
Depending on how bright you want your print to look on black will determine whether or not you lay down a solid white base or not. If you want bright, vibrant color, then yes, you should lay down a solid base. If you're going for a darker or distressed look, you can halftone the white base. Halftoning the base gives the shirt a lighter feel and breathes better than if you have a solid base, but again, the colors aren't as bright.
Flopspop -question
If your screen angle is the same for all the screens, wouldn't the dots lay exactly over each other (assuming they are lined up correctly)? That wouldn't be good would it?
That is call moire I believe. Also why did you convert it from X3 to a bitmap? If your colors were CMYK in X3 you caould just print your separations from there.
Printing CMYK 
