Converting CMYK values for printer...

[niceShoot]

I don't do a lot of non-digital work, sorry if this is newbish.

I'm working on retouching a large poster file that's an amalgam of a bunch of images that were provided in RGB. They were converted to CMYK and the final image was flattened and provided to the printer as a PDF. The printer came back at us stating that the CMYK values were 59-50-50-16, and that he needs them to be 14-11-12-60. My first thought was, uh, you can't take care of that?

What exactly should I do here? I'm surmising that this is an ink coverage issue, but how do I go about setting the individual CMYK value of the final image this way? Channel mixing? Selective color adjustment layers? Seems to me that I'm missing something here.

 

[Tom Mann]

OP: "...The printer came back at us stating that the CMYK values were 59-50-50-16, and that he needs them to be 14-11-12-60. My first thought was, uh, you can't take care of that?..."

Your thought is exactly what mine would have been. In fact, because of the zillions of combinations of presses, press settings, inks, and papers, I'm finding that more and more (most?) low-to-moderate volume printers who have kept up to date are requesting files be sent to them in sRGB, and they do the conversion themselves. The next most common (but still reasonably accurate) approach is that they supply their customers with an ICC profile for their particular printing operation. The worst of the lot are those who are unaware of modern color management and make statements such as the one you encountered.

An outlier in this spectrum of printers are the high volume presses (eg, large circulation daily newspapers, magazines, etc.) who almost always deal with the same content generation people and may even still have some old-fashioned pre-press staff to handle such issues.

So, my first question to you is, "do you have to use this printer?".

With respect to your technical question, his request to you does indeed have to do with ink issues, but it's almost certainly because they are always trying to save on more costly color inks (the pressmen are always under pressure to do this). Furthermore, my guess is that this company is geared more towards low-cost high-volume printing for businesses, versus short-run fine art printers who guarantee rich, neutral blacks.

If you are going to stay with this printer, the relevant procedure to try to accommodate his request is called "maximum black generation" (Google it). Here's a good link:
http://www.b4print.com/index.php?topic=6859.0

My guess is that if you get anywhere close, he'll be happy because he is using more black ink and less color ink. OTOH, you may not be happy because doing this can easily muck up delicate colors such as flesh tones.

HTH,

Tom M

PS - I do assume you are dealing with an offset press, not some poor uninformed soul running a wide-body inkjet who thinks it must be fed CMYK files (ie, instead of sending it RGB files and letting the printer driver handle the conversion for any of the authorized combinations of inksets and papers).

 

[niceShoot]

Tom, hey thanks for the fantastic reply! Unfortunately, I don't know anything about who's printing this as I'm at least a few levels removed from that end of things. The project if for a large university and I know that it's passing through multiple departments and approvals on its way to press. I suspect that the project was probably bid out and that yes, we're stuck "working with" whoever it is that they've already selected.

My immediate reaction to being told that they needed new CMYK values was to ask if they had experience with this printer, and to insist on a hardcopy proof before signing off as the request seemed "odd" to me for a professional shop. The design is littered with a wide variety of skin tones so color accuracy is a pretty big concern.

I'll read up on your link, thanks for the lead! Hopefully I can get this straightened out.