Document CMYK vs Working CMYK in Proof Setup

So maybe harmonize the two differing color managements by going to InDesign > Edit > Color Settings and setting the colorspace to the custom CGATS21_CRPC.icc your commercial printer sent to you. Even better, I recommend you travel upstream to Photoshop > Edit > Color Settings to set this all up and turn on the Convert switch choice to force all documents to convert to the custom commercial printer colorspace icc profile. While there I save/name a .CSF (color settings file). Then, go to Bridge > Edit > Color Settings to send out a command to change to this method which affects AI and ID. Then, go to InDesign > Edit > Color Settings to verify that it made the change to your custom CGATS21_CRPC.icc profile. Do this step with no documents open. After a restart of InDesign, open your InDesign document. It should convert to your custom icc profile. If not, you can go to InDesign > Edit > Assign Profiles and set it there. The net result will be that the SWOP profile will be gone and only your custom icc profile will be at work. If you use Overprint Preview or if you turn on Proof Settings/Proof Colors, it will be your custom CGATS21_CRPC.icc profile, and this should end your two-outcomes confusion.

[It is also a great idea to calibrate your monitor with a colorimeter so that your monitor can accurately show YOU the tonality of the custom .icc profile.]

i can't find any explanation in the help menu as to the difference between Document CMYK and Working CMYK.

Hi @jmad70 , The difference is: Working CMYK is the current Working CMYK Space you have set in Color Settings, and Document CMYK is the CMYK profile that is assigned to the document—the assigned CMYK profile for an existing document can be set from Edit>Assign Profiles...

It is the assigned document CMYK profile that color manages the document’s CMYK colors and any conversions you make from RGB to CMYK. To soft proof the output to Document CMYK you don’t need to turn on Proof Colors—turning on Overprint/Separation Preview gives the most accurate soft proof to the expected document CMYK output space.

In your capture you have US Web Coated SWOP assigned to your document, so you would want to fix that problem and assign the printer’s CGATS21_CRPC.icc profile, then turn off Proof Colors and turn on Overprint/Separation Preview.

You've opened a Pandora's Box of sorta known and entirely unknown technical and aesthetic variables when we start talking about "good color." This won't be a short read, but I'm hopeful it'll be worth it to you as you proceed with commercial printing of your InDesign job(s).

I'm simplifying here a lot, but Web Coated SWOP is a generic standard, generally used as a measurable target for printers to attain. Printers use it as the target to define how their press process will reproduce your work. No matter what equipment inks or specific paper stock you use, if you lock up a big roll of coated paper to your web offset press and match Web Coated SWOP specs, you can ensure you can deliver consistent, quality results. 

Please note that I wrote ensure, with an e, rather than insure, with an i. This isn't an absolute guarantee; it's a target printers use to get good results.

Now your printer's ICC profile is a whole 'nother story. That profile is custom-tailored to match exactly what the printer's equipment can deliver when reproducing your work. If the onscreen image looks better, that's a happy coincidence that may ensure you get a better result with your chosen printer than than one maintaining that generic standard. Or it may not.

Is your monitor regularly calibrated to portray accurate reproduction? Most folks are not. Is your monitor regularly calibrated to accurately reflect your printer's specific ICC profile? Unless they do that for you, I'd just about guarantee not.  Even if you choose the correct monitor profile, your monitor needs to be calibrated to accurately match. Using the profile helps, but you need monitor calibration if you want to get to "perfect" matching. The only perfect matching you'll ever see for your job are the first useful sheets that come off the press.

Mechanical proofs (print geezers just call them mechanicals) run off prepress materials are close, if you're not using a digital press which has no interim steps. Printer-provided digital proofs are not run off prepress materials to print your job, but are run off your digital files. They can be as good as mechanicals and are your only option if the job will be run off digital presses. But any of these will likely be more accurate than what you're seeing off an uncalibrated monitor.

After saying all this, the only proof you can get that is of any importance is what your printer calls a contract proof. However your printer generates that proof, a contract proof insures, or guarantees, that's the result your printer will deliver from your InDesign files when the job comes off the press. Everything else is just an estimated guess.

If color is absolutely critical to the success of your job(s), it's worth the extra expense to have your printer provide contract proofs that you can approve of before you ever print the job. It's an extra expense, but valuable insurance that mistakes on your part and/or your printer's part don't turn into expensive mistakes coming off the press.

TL:DR — Don't trust how your job looks on your monitor. If it's critical, get a contract proof from your printer and make sure it's just the way you want it before you print your job. Doctors may bury their mistakes, but print graphics folks make them thousands and thousands of times each time they really screw up.

Hope this helps, and good luck with your job. I hope it turns out great for you.

Randy