Correct color settings--CMYK vs Process?

[andybean224]

This one stumped my service bureau.

I'm in Quark 4.1. If I set up a color as a process color in the color settings (Edit > Colors > New > Model=Pantone Process) and then I change the Model setting from Process to CMYK, the color changes dramatically in the new/original boxes below. Can someone please explain to me why a process color that is broken down into CMYK would look different when switched to CMYK? What's the difference between these two options? And how am I supposed to set up the file properly for offset printing?

FYI, I want to print something with Pantone DS 192-9 C, which is a coated process color and appears light purple in my Pantone fan. When I select it using the process setting, it appears blue, and then it changes to purple when I switch from Process to CMYK. But my laser proofs came out blue. What's the story?

Thanks!
Andy

 

[jimoblak]

The reason why you use a Pantone fan is because colors are not accurately represented on screen. Do not trust anything that you see onscreen.

The CMYK color model is not capable of producing every color. That is one reason why Pantone makes colored inks. Trying to dumb down a pantone spot color to process often causes color shifts when the program tries to approximate the original pantone color.

Compare the CMYK values shown in Quark with the CMYK values printed on the Pantone fan. Do they match?

- - picklefish - -

 

[andybean224]

Hi picklefish. I understand why this would happen from a spot color to a process color, but why when going from process to cmyk? Aren't they the same?

My pantone fan says the color breakdown is 25-20-0-0. Quark also says that, and on screen in the document it actually looks correct. But when I output it at my service bureau, the purple came out blue. I'm trying to figure out why and had the thought that the ripper may be picking up the initial process color (which appears blue) as opposed to the CMYK version, which is purple... Does this make sense?