“To make sure the color you see on screen comes as close as possible to simulating the final printed work:
– Your monitor must have its own custom ICC profile.
– Your application’s Color Settings must suit the intended print condition (GRACol, SWOP, etc) default Adobe Color Settings
– Keep images in RGB as long as possible but remember they may be less colorful when printed, depending on the gamut of the printing system.
– To see how an RGB image will look when printed, select Proof Colors (CMYK preview) (Mac: Command + Y, PC: CTRL +Y)
– Always embed the profile when saving images. This happens automatically with default Color Settings Files from G7 web page.
– The only purpose of a prepress proof is to simulate how the job will appear on press.
– Prints made on an un-profiled desktop printer are NOT PREPRESS PROOFS
– Proofs and press sheets should be vieweed under ISO-standard D50 lighting. Non-standard illumination (eg office fluorescent tubes) will often cause a good proof or press sheet that looked acceptable under D50 lighting, to look unacceptable.
– There are over 100 variables in a typical printing process, not all of which can be controlled by the printer.
– It is theoretically impossible for even the most skilled printer to EXACTLY MATCH a prepress proof.
– It is theoretically impossible to reprint a job exactly the same way twice.
– Good printing should look close to the proof in the most important colors, but will always have some small differences
– Generally, the closer the match you ask for between proof and press, the more the printing will cost.
– If the proof and the press sheet are printed on different colored paper, expect the image areas, especially lighter colors, to be affected by that difference. ”
From Printing Guidelines 2011- Full version here: http://www.ipa.org/files/DEER%20Printing%20Guidlines%202011%20Poster_print%20only_Oct10.pdf