Mar
6
Why Printers Don’t Want RGB Files And Why That Should Change
Filed Under Color Management, Digital Imaging, Herbiology, Images in Print, Memo from the Pressroom
Have you ever wondered why printing companies request that files be sent to them in pre-separated CMYK format? Well, wonder no more…
While printers claim that they don’t want the responsibility of converting files to CMYK without the customer seeing the files after conversion from the larger RGB color space to the always-smaller CMYK space, that is only part of the reason.
Truth is that the printer traditionally almost never performed the color separation of photographic images before the era of desktop publishing. That science was left to a now-absent trade expert known as the engraver, or as he is now known, the color separator. The engraver is the one who knew how ink acted on different papers and presses. He custom-tailored separation films for each printer based on the press and the paper being printed upon. The engraver was, in effect, the profile maker of a prior generation.
Now that the engraver has been swiftly and silently replaced by a benign button on desktop publishing software, the whole industry is suffering the loss. The designer never understood the color separation process and precious few printers ever had to perform the magic either. So here we sit, somewhat confused by the problem. Each party assuming the other has the solution.
So what needs to happen?
One party or the other needs to belly up to the bar and learn the science. While this is a reasonably-accurate suggestion, it is not the ultimate solution to the problem. In my humble opinion, the responsibility actually lies totally and unequivocally on the printer’s table.
Only the printer determines the press and paper on which each project will be run. Only the printer can measure the response that ink will have to each. Only the printer can profile each paper and ink. And now that reasonably-priced and easily-operated equipment and software is readily available, only the printer must respond to the challenge and assume the lead in this process. Periodically (when new untested paper lots arrive on the floor), the printer must mount the color patch test plates on press, bring inks up to production densities, and print the charts on all previously-untested papers. When the tests have dried, the patches on these test sheets must be read and profiles generated. Once the profiles are generated and verified, they should be distributed to all clients for use either as conversion or preview tools.
Whether or not it is his fault that the electronic publishing industry chose to go in this direction is immaterial, it is ultimately the printer who stacks the paper in the press and prints the job. It is therefor the printer’s responsibility, indeed his privilege, to learn the science and regain control of his press room and let the designers concentrate on what they do best… design!
Think about it!
©copyright 2008 Herb Paynter
http://www.imageprep.net
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9 Responses to “Why Printers Don’t Want RGB Files And Why That Should Change”
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[...] Original post by birdbrain [...]
[...] out Why Printers Don’t Want RGB Files And Why That Should Change from imageprep.net. I’m a designer constantly dealing with converting RGB to CMYK conversion. [...]
Are you saying that sending RGB to the printer is better because the four color process that extends the range of CMYK could not advantage from using a CYMK image because the colors have already been clipped. However, in RGB the color values are preserved and can still be Converted prior to the less constricted CcMmYK and are still viable? Here will the conversion occure from RGB to CcMmYK?
My contention is that printing companies should take the lead in the RGB>CMYK conversion process and not leave this process to a designer. The printer has (if he purchases the measurement equipment) access to the information that allows him to produce CMYK profiles for all his house (stock) papers. If he were to provide these profiles for his clients everybody would see improved results.
Do you think that the only way to make use of a CcMmYK press setup is to send RGB files?
Certainly not. Most printers still insist on you sending them CMYK files. Until such time as your printer actually does build profiles for his “house stocks” (the papers he normally keeps in stock), you should use the SWOP (coated or uncoated) profiles found in your Adobe software. However, I still contend that your printing results will improve considerably when custom profiles are provided by your printer.
Why is it recommended that the designer send a seperations PDF file to the printer when most printers will only be using the original file or Printer file to send to their own RIP? I am left wondering about the purpose of the separations file? I was told that the printers just use this as an assurance against any issues they may encounter with creating the printing plates? Is there more to this?
While a printer’s RIP can perform the RGB>CMYK conversions, they prefer that you do the conversion before it gets to them simply because they don’t want to bear the responsibility. If you send them CMYK PDFs, those files get sent to the RIP but pass straight through to the platesetter as CMYK files. If RGB files are sent to the RIP then they are converted on-the-fly inside the RIP.
I was assuming that the files would be in CMYK mode. Part of what you said was the printer does not want to bear the responsibility-is there anything about sending a CMYK Seps File that can be further explain by such a request?