Non postscript printer color difference

Question

i am trying to understand when the colors i use in Illustrator or CorelPainter IX print differently than what is on the monitor - I just did a handpainted project in Painter - I scanned in the sketch to Illustrator and hand sketched over it to Illustrator - I then brought it into Painter to color - I dropped all of the layers and placed it into Illustrator to finish it - when it printed it gave me the message of colors will be different when i print on a non postscript printer - i don't remember ever getting this error before - i was going out to kuler to get colors and "making" them in painter by using the rgb values - after all this work it printed different in both Illustrator and PS - any help or tutorials on colors, printing, and non postscript printers would be helpful - i am also going to call my printer's customer service dept to help me out on this - thanx in advance O_O

Answer 1

If your Illustrator document color mode is CMYK, you must print to a PostScript device to ensure accurate color. That can be a printer with native PostScript firmware or something like a typical inkjet printer (an RGB device, CMYK inks notwithstanding) operating via (usually) optional PostScript RIP software.
A non-PostScript printer expects RGB data. When you print a CMYK document on such a device, a color space conversion must occur somewhere. That conversion is out of your control; hence, the unpredictable color.
You have several choices:
1. If your output is to your non-PS printer and
only that printer, work in RGB mode in Illustrator. You will then have the full range of color management options available to you.
2. If you must work in CMYK (because you are ultimately going to press) and you wish to do local proofing, buy a PostScript printer or, at least, a third-party PostScript RIP for your existing printer, if available.
3. You can use the "poor man's proofing" method: Assuming you have Acrobat,
print (not
save, not
export) to PDF using settings that convert to sRGB (e.g., for screen viewing). You can then print the document on your non-PS printer from Acrobat (or AI) using RGB color management. It's not the same as #2 above, but your colors should be reasonably accurate. This works because the Acrobat Distiller engine is, in fact, a PostScript RIP.