Photoshop CMYK Tips
A collection of tips for working in and with the CMYK color model in Adobe Photoshop. These tips offer you some insight knowledge about working with CMYK that mostly only experienced graphic designers can tell you.
Better printed gradients
If your working on a image that will ultimately go to a printing press in CMYK mode ( to be used in a Adobe Indesign document example) and it's going to contain one or more gradients, you'll get better printed results (less color shifts) if you create those gradients after you convert to CMYK mode.
Once you go into CMYK mode, don't go back
Once you convert to CMYK mode do not go back to RGB or Lab mode for any reason. Once you converted to CMYK mode, the data loss from the conversion has already occurred and switching back to RGB won't bring back those colors. So if you go into CMYK mode don't go back. More information about RGB mode CMYK.
Better flesh tones in CMYK
When your sharpening CMYK images one of the toughest areas to sharpen are the flesh tones. Most of the time, because of the smoothness of skin, you'll need a lot of sharpening. Sharpening flesh tones can introduce noise and color shifts. You can combat this by only sharpening the Cyan channel in the channels palette. Remember: this will only work for images in which flesh tones are the focal point of the image (such as in portraits).
Are your colors press ready?
If your working in CMYK mode and you sample a color that's outside of the range what CMYK press can reproduce you'll get Gamut Warning right within Photoshop's color picker.
It's tiny but the gamut warning is there.
Just below the warning symbol is a tiny color swatch showing you what that color will really look like when printed. Click the swatch to select that color within the Gamut.
Make color corrections in CMYK or RGB mode?
As a general rule try to do as much color corrections as possible in RGB mode, you'll have more (color) data to work with and more adjustment options in Photoshop. Switch to CMYK mode as a last step in doing pre press work on RGB images.
Using the Unsharp Mask in CMYK images
If you made the mistake and already saved your image in CMYK mode or you got a image delivered in CMYK format and you want to sharpen it without introducing color shifts or halos, go to the Channels palette, click on the Black layer channel, and apply your Unsharp Mask there. Applying the filter just to the Black channel will enable you to apply a higher level of sharpening without damaging the image.
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