Graphic Design Stack Exchange is a question and answer site for Graphic Design professionals, students, and enthusiasts. It only takes a minute to sign up.
Sign up to join this community
When I convert from RGB to CMYK in Photoshop as you know colors change saturation and maybe some hue.
So basically what the title asks, does it matter when I adjust the colors and saturation via hue/saturation layer? Or can I fix the colors in RGB or in CMYK and it doesn't matter?
Actually, to do things correctly you need to color adjust at least twice.
If you are working in RGB, you should color correct in RGB.
And if you then convert to CMYK, you should color correct again for CMYK.
One color correction is never a good idea if you change color modes.
What I found reading a great book by Dan Margulis "Professional Photoshop: Color Correction, Retouching, and Image Manipulation With Adobe Photoshop" is to work in Lab. When I was working for newspaper and we had a custom made profile RGBtoCMYK so we worked only in RGB. BUT we printed on only one machine that has been profiled to our needs. So we had a profile that converted our corrected RGB to CMYK in a way that gave the best results.
When I tried to apply same workflow in my freelance job I failed miserably (correcting in RGB then changing to FOGRA 29 for example). Sometimes the RIP omitted profiles, sometimes it applied it's own. Sometimes the printhouse had it own profile so my CMYK was far away from result (machine added 10% Magenta while I had none).
So after reading Margulis book I started working with photos in Lab. And it worked great. And by great I mean that even serious mistakes didn't have much influence on photos in the end.
If you plan to prepare a project for printing, go straight to CMYK mode and calibrate your color as the first step.
Color correction should be the first step since you might need to choose the layout's Pantones or CMYK colors that fit with or is from your pictures...
Usually in the printing industry, this is the first step because all the material is prepared first by the "color management" team and then sent to the designers. Then some adjustments can be done again but they are usually minor. The same process is logical for freelance designers.
If you calibrate your colors at the end, you could 1) forget to do it or 2) have mismatch in your layout and then have to change your CMYK recipes in it it (or them) (eg. InDesign, Illustrator, etc.) It's efficient to do it as first step and then build your layout on a solid foundation!
If you received quality pictures from a photographer or bought stock pictures, the images are usually already well calibrated in RGB and they don't require a lot of adjustments if this step was well done.
If your file is delivered in RGB (e.g. from a stock library or photographer as stated above) you should colour correct / airbrush / do your creative interpretation on the RGB file first (keeping an unchanged original as a backup). If you know you are going to professionally print the image (e.g. lithographic), then once you are happy with the results you can convert to CMYK (still in Photoshop) and counter any loss you see from the change in format - i.e. adjust again. Then bring into an Indesign document set up for print.
The reasoning is that RGB has a wider colour range (gamut) than CMYK which is why photographers and stock libraries deploy it. It's logical them to work / manipulate the best possible resource you have.
If the image is delivered to you as CMYK and you will only use it for print, then you have nothing to lose correcting in CMYK as the wider colour range isn't present and wont be used. However, if I had an image delivered in CMYK for use as a website banner or backdrop, I would convert it to RGB and put colour back into it to improve impact and saturation for screen use (but that's another story).
Hope this helps
