I know how to screen print solid colors but how do you use a say a 6 color press to make a realistic picture with fading colors and shades? I would guess you'd use photoshop instead of illustrator when it comes to this?
This is how i make my halftone stencils but only 4 process colors are used, there might be better way for better result out there though..
1. Open file in photoshop
2. Layer -> Flatten Image
3. Image -> Mode -> CMYK
4. Window -> Channels (To show the Channels window)
5. Click the little arrow button under the [x] button that closes the Channels window -> Split Channels.
You should have 4 greyscale images now each for the CMYK colour.
6. To halftone the images, goto Image -> Mode -> Bitmap. Enter the resolution desired, LPI (lines per inch), angles and dot shape for the halftone.
My advice is dragging the image to a blank printing paper sized template before halftoning (step 6) for correct dot size. Angles taken from photoshop are C 105, M 165, Y 90, K 45.
I got this from a tutorial in Google(cant remember the link) so this might not be the proper way and might not get professional results.
i think the method you want is index separation. ive never done jobs that require index separation. try using live trace feature in adobe illustrator and convert the image to the number of colours you want, then switch off the colours thru the swatch panel for printing.. but this is probably not the proper way to do it...
10 color autos are great for spot colors or simulated process. A good program for simulated process is FastRip. I've never used it but have read reviews.
For realistic photo type of printing, the only way to go is four-color-process. Just make sure you mark your seperations with each color that comes out of your printer to keep them straight. Cyan, magenta, yellow and black. If your going to print on a dark shirt, make a negative of the picture for under-basing with white.
It's not that hard after you do a few and wet those little feets.
.
__________________
Work Harder, not Smarter...no, that's not it...Work Harder and Smarter...no...Work Hardly Smarter...NO!...DangIt! Just get to work!
There are several kinds of separation. CMYK (generally not good) Index (uses same set of colors to reproduce all colors) Spot (designer chooses exact PMS colors and printer mixes ink to match). I am a Spot designer/Separator who relys heavily on my PMS book.
that piata shirt could be done with 2-3 colors. The black halftone the copper green and maybe a darker shade of green.
Here's how I would sep it:
1. Flatten image
2. select color
3. save selection to layer
4 repeat for all major colors
5. add layer with reg marks
6. save one layer at a time as jpg
7. close art file
8. open all jpgs
9. convert jpgs to b&W
10. color mode greyscale
11. merge channels
12. assign pms color to channel
13. review
Last edited by kindred; July 3rd, 2007 at 06:16 AM.
Index seps you can use fast films but it runs about 1000 bucks a license. works really well and is pretty fast. past experience when i was with other companies tech support isn't too friendly.
How to make real picture prints 
