Ensuring Good Colour and Saturation When Printing

[Alex37649926gy3i]

Hi everyone, 

I'm working on a magazine in InDesign in RGB and am preparing it to print on uncoated paper with a commerical litho printer. I know that I have to convert to CMYK, but am told that this conversion (and then printing on uncoated paper) will make all my pages/images a lot paler. 

My question is how can I accurately predict what my pages will look like from a colour/saturation perspective? Is there a way to look at my digital file on screen and have a closest estimate to what my RGB InDesign files will look like when litho printed from a CMYK printer on uncoated paper? I just want to know if I need to make my pages more saturated and have more contrast so it looks good printed.

Also, is there a best way to convert to CMYK when my entire InDesign file is in RGB? Is it a good method to export the whole thing to PDF and convert to Document CMYK (numbers preserved)?

I'm a newbie to this so appreciate your time and any help I can get!

[James Gifford—NitroPress]

To start with, the one and only expert on getting a perfect result is your printer. Not a printer, not some print specs you look up (or get here) — the guy who will actually be feeding paper, ink and your job files into the press. They will have specific requests for color model, screening, etc.

Backing up from that, yes, there are some general rules about good comp in ID and good prep for export. I'll let better experts take it from there (and there are some here).

[Willi Adelberger]

Images should be in RGB when you place them in InDesign. They have to have a valid color profile. But you have to turn on the CMYK proof preview. So will Photoshop simulate the CMYK result of a RGB image during work in that program. You can even see the four CMYK plates. This command is found in the View menu. 

Not all RGB colors can be represented in CMYK process. 

For texts and (vector) graphics in InDesign you should work from the beginning in CMYK. 

[rob day]

I'm working on a magazine in InDesign in RGB and am preparing it to print on uncoated paper with a commerical litho printer.

Hi @Alex37649926gy3i , The document’s assigned CMYK profile (Edit>Assign Profiles...) determine the CMYK values and appearance you will get on a conversion from RGB to CMYK. If the print destination is an uncoated sheet on an offset press it will be important to at least assign an uncoated profile, e.g. Uncoated GRACoL 2013.

Your printer should recommend the profile to use, but they may not—in that case use one of the InDesign uncoated profiles and make sure you get a contract proof before going to press.

With an uncoated profile assigned, all you have to do is turn on Overprint/Separation Preview in order to get a soft proof and the output values of the expected Document CMYK output. So with Overprint Prview off this AdobeRGB image displays with the full RGB gamut:

With Separation Preview on the appearance and output numbers are the expected Uncoated GRACoL output:

[Alex37649926gy3i]

Thanks everyone for the replies. My follow-up question is this: is the best workflow to export my entire InDesign file to a CMYK PDF? When I do this, with "convert to destination profile (preserve numbers)" and Uncoated FOGRA29 as a destination, my PDF looks absolutely fine. Is this an accurate reflection of what the print will look like?

However, when I have my export settings to "inlude profile", my PDF export looks rather pale, akin to how my InDesign document looks when I proof the profile of Uncoated FOGRA29.

Moreover, I now see that my printer requests a PDF/X-1a file and FOGRA39, but I know there is no uncoated FOGRA39 profile available - only coated. How do I work around this for accuracy?

Also, is the solution to export each page and brighten/boost contrast in Photoshop before plugging back into InDesign? 

Thanks again!

[James Gifford—NitroPress]

I can't tell if you grasp color gamuts or not, but RGB color covers a much wider gamut than CMYK, with many much-brighter colors than the latter can reproduce. An extremely vibrant layout with colors defined in RGB and images in RGB is not going to export, convert to or print anywhere near that vibrantly given that process printing is limited to the CMYK gamut.

It's not too sweeping to say that nearly all of print preparation and optimization past simple layout on the pages is concerned with color management and getting an optimal result on the very specific press/inks/paper/process to be used.

That is: unless you carefully use CMYK color in your layout so that the work is more natively WYSIWYG (not really the best idea, for several reasons), you have to accept that your PDF and print output is going to be some degree duller, less vibrant as colors are rendered into the smaller gamut. (Working in RGB for CMYK export is the correct, modern workflow for most print work... you just have to understand how the colors will shift through the process.)

[jmlevy]

Moreover, I now see that my printer requests a PDF/X-1a file and FOGRA39, but I know there is no uncoated FOGRA39 profile available - only coated.

Fogra 39 is a profile for coated paper. For uncoated paper, you could use Fogra 29.

[rob day]

However, when I have my export settings to "inlude profile", my PDF export looks rather pale

It’s important to note that the PDF/X-1a preset Standard doesn’t allow embedded profiles. PDF/X Standards do include an Output Intent Profile for handling the softproof preview of document CMYK values in Acrobat, but document CMYK colors Export with no profile. With PDF/X-1a all color is converted into the Destination CMYK space so you don’t need a CMYK profile to be embedded because there will be no further color managed conversions—the PDF’s CMYK values are correct for the destination press.

my InDesign document looks when I proof the profile of Uncoated FOGRA29.

Also, you should have the same Uncoated FOGRA29 profile assigned to the document. In that case you don’t need to use Prrof Setup/Proof Colors because Overprint/Separation Preview is already correctly proofing to the assigned CMYK space.