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Managing Color in RGB-CMYK Conversions

(May 2008) posted on Fri May 02, 2008

Find out how image-file preparation and color-space conversion can affect color control in prepress and digital print production.

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By Rick Mandel

Responsibility ultimately falls on the color manager. Should the printer bear the liability associated with converting the file to the printing mode of CMYK or shed the accountability and require the client to supply the file already converted? The upside to conversion by the printer is that the printer has more ability to match a proof within an RGB workflow. The downside is that the client can claim your conversion process resulted in failed expectations, which is a very nebulous concept to prove.

The client who is very concerned with conversion standards is one who converts the file before producing the proof and then gets approval. Profiles then may be attached to the converted file, which advances repeatability. Advertising agencies despise surprises and, for the most part, attempt to lock the printer out of the ability to alter the file. RGB-to-CMYK conversion is a type of file alteration. A variety of results may stem from a computer’s alteration of a graphics file—even the smallest amount. Then we ask how the bizarre anomalies cropped up.

Always keep in mind that a profile is a representation of the proofing device at the time of performing the profiling process. It doesn’t prove that the proofing device, regardless of technology used, is calibrated at the time of proofing the project. The embedded profile could throw your RIP down the wrong path. Your knowledge of the client’s file preparation/proofing work-flow and expertise is critical.

So, how do we want to instruct our client in file production in the context of color-space decisions? I believe the answer lies within the relationship with the client, knowledge of the client’s file-preparation and proofing workflows, the digital printing workflow, and how much responsibility the printer wants to shoulder. If I had a choice, I would select two scenarios:

1. A good relationship and trust with my client would allow me to request an RGB file with or without the attached profile. I know I could produce the best results with the latitude that RGB provides.

2. A new client, or one who seems to need control of the process, would warrant a request for a converted file with or without the attached profile. The window is smaller in this scenario, though informing the client beforehand about what to expect creates trust. This controlling customer may surprise you and be elevated to a relationship client in the future.

Our customers have the ability to perform tasks that were previously exclusively our domain, which means it’s vital for us to understand their abilities and inform and educate them. As always, communication with the client is the defining connection between success and failure.


Rick Mandel is president/owner of the Mandel Co., a 110-year-old graphics firm. He also serves as CEO of Screentech, a division of the company that specializes in large-format color separations for the screen-printing and P-O-P industries, as well as large-format digital imaing. Mandel is a speaker for SGIA, SPTF, MWSPA, POPAI, and more, and he's a member of the Academy of Screen Printing Technology.




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