CMYK: Masks with alpha transparency, greyish border?

[bellyanalytical]

Hi,

I am not sure if this has been asked before, but I couldn't find anything about that. Also I have no comparison to Adobe right now - no subscription.

 

Why is the mask in CMYK not really „alpha-masking“ the magenta layer but turning the edges grayish? How can I avoid that?

 

thanks and cheers,

Steffen

 

CMYK:

 

 

RBG:

 

[Lee D]

Hi bellanalytical,

 

Are you using pure black (100/100/100/100) on the CMYK sliders?