Fixing colours to fit CMYK

[ninthsymphony]

I made a colour illustration by hand, scanned it, did minor editing in Photoshop, used it in InDesign for a book cover, but when changing to CMYK before printing it loses all the brightness of its colour. It is a light purple colour, but turns darker and dirtier. I understand why it happens, but what is the best way to fix it? I have tried adjusting saturation/hue, Vibrance, color balance and brightness/contrast, but have not succeeded. Any suggestions that might help?

[Test Screen Name]

Are you sure you understand why it happens?

If you are sure, is the colour shown as out of gamut? Are you using the correct CMYK profile?

[olga_dav]

I think the best way you try to fix this issue in Photoshop before importing to InDesign.

Figure out which color profile your printer uses, then work with CMYK colors and color fields to get the idea how it will look exactly on the paper. Test prints of your work are also always helpfull.

Hope it helps,

Best,

Olga

[c.pfaffenbichler]

As mentioned already it is essential to know the correct CMYK Space.

Then one can, while working on the RGB image, use View > Proof Setup > Custom to define a Proof Condition and use it to preview the CMYK result.

If it should become necessary to edit in CMYK one can maintain the RGB image as a Smart Object in the CMYK file.

What is the image’s exact Color Space?

With a small one like sRGB it could be that you are not fully exploiting the CMYK target space’s gamut.

[cmgap]

Here is a test for you:

1. Leave the image as-is in RGB mode in Ps and save as a psd

2. Create a new document in InDesign for your cover

3. Import the RGB image as a psd into your InDesign document

4. Save InDesign file

5. Go to File >Adobe PDF presets > choose press quality

6. Ask your printer for the settings for output and create pdf

Color conversion will be done via Acrobat - a common printer profile in EU is Coated FOGRA39

Your output from your own printer will be quite different than what will be produced by your printer so that is what you should be looking at for color accuracy.

[D Fosse]

This sounds like a straight out-of-gamut case. No procedural tricks can bring a color into gamut if it's outside in that particular color space. It just can't be reproduced. It's a hard limit, a brick wall.

That said, make sure the color space / profile is in fact the correct one to use in each particular instance.

[Derek Cross]

As D Fosse states, there are a number of colours, such as bright orange and bright green, that just cannot be reproduced in CMYK. You can have special extra  spot colours but they can only be used for things like text and colour panels (not images).

[ninthsymphony]

Thanks everyone for responding! It helped a lot, though I have realized it is not much I can do fix it.

The colours are out of gemut, the image is in adobeRGB and I wanted it in CMYK Coated FOGRA39, which is what the printing place wanted. I was hoping I could change it into a colour closer to what it should be, but I have learned a lot that I will remember 'till next time

[Derek Cross]

Adobe RGB has an even larger colour space!

[cmgap]

Why You Should Import RGB Images Into InDesign and Convert to CMYK On Export

For reference - you may find this article helpful: https://indesignsecrets.com/import-rgb-images-indesign-convert-cmyk-export.php

[Norman Sanders]

The printing of book covers or book jackets is a cost element that often forces you to work within the limits of a four-color ink gamut. For additional economy, your cover may even be “ganged” (positioned on the same press sheet) with the publisher’s other four-color covers.

However, there are occasions (thank goodness) when budget constraints are eased up a bit and allow for additional ink color(s) called “touch plates” or “kickers” to add a fifth or sixth out-of-gamut color, or metallic gold or silver. It never hurts to ask whether the budget could accommodate such a request.