Way back when, because all their "camera-ready" art was done in black and white, designers would specify screen tint color builds by using published reference Color Atlas guides like the generic Kuepper's book which showed examples of hundreds of CMYK screen tint build combinations:Or this poster of screen tint combinations:Because they were based on, loosely defined (at the time) universal standards, the use of a color atlas, in my case, even allowed me to communicate color for presswork in countries, like China, where I did not otherwise understand the language:The prepress shop/printer would use pieces of screened film, according to my specification of X% Cyan, X% Magenta, X%Yellow, etc., stripped into flats to create the image on plate that would result in the requested color on press. Today, that specification happens in an illustration or page layout program – however the principle is the same.
Of course, a generic Color Atlas could not reflect the color performance of an individual printshop. As a result many printers would create, and provide their customers with their own unique CMYK Color Atlas like this one from Agency Press with the same screen tint builds printed on four different types of paper:As long as the creative specified their color builds according to the printer's guide in the Atlas they would have a reasonable expectation as to the color that would happen on the press. Some might argue that this is ancient technology, however, for printers who want to clearly set print buyer expectations - a Color Atlas still represents the reality of actual "ink-on-paper" performance – especially if the printer's presswork is outside of industry norms. For example, Hennegan Press:who wanted to show their color capabilities with 10 micron FM. Or Fort Dearborn in Chicago helping their customers specify 7-color process printing with their HiColour system (also FM screening):or Anderson Litho communicating their ability to mimic metallic paint for car brochures (also FM screening):or Intelligencer Printing demonstrating their metallic print capabilities in this superb brochure (also FM screening):Even with today's sophisticated color management systems, the savvy printer would do well to consider producing their own Color Atlas to smooth the color communications channel with their customers - especially if the print shop is doing work beyond the mundane standards for color printing.
Update December 15, 2009: Heidelberg has just published their own color atlas - click on this POST for details: