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A
active_appreciator89724
Participant
January 23, 2025
Question

CMYK build converts to 100% black when changed to grayscale

  • January 23, 2025
  • 5 replies
  • 230 views

I'm working with a customer supplied file that uses a dark gray built cmyk color 69/64/62/59. I'm trying to convert it to see what percentage of black it will be. When I convert the color to grayscale, it changes to 100% black, instead of a halftone of black (40%, 65%, etc.). This seems to be a glitch, but maybe there is a setting I'm missing.

5 replies

Ton Frederiks
Community Expert
Ton FrederiksCommunity Expert
Community Expert
January 23, 2025

And if you paste a rectangle with those values into an RGB document, you will see a much lighter color than 0/0/0.

Either let you guide by the Photoshop conversion or the RGB > Grayscale. Or eyeball it.

Ton Frederiks
Community Expert
Ton FrederiksCommunity Expert
Community Expert
January 23, 2025

I don't think that a 100% gray/black is the correct conversion. Photoshop thinks it is an 88% gray.

B
Community Expert
Bobby HendersonCommunity Expert
Community Expert
January 23, 2025

The gray formula you listed adds up to 254. That's a pretty high total ink number, just 46 points shy of what passes for a 300 rich black. The 254 gray appears slightly lighter than a 100% K black displayed on-screen accurately (Illustrator defaults to displaying 100% K black as rich black).

Monika Gause
Community Expert
Monika GauseCommunity Expert
Community Expert
January 23, 2025

Greyscale by definition is a percentage of just one color: black.

 

And the color mixture you have there will print pretty dark, so 100% seems legit. But of course you can just drag the slider to a different value.

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