CMM simple or intelligent


I’ve been doing some tests to isolate the behavior of a particular CMM.

I am trying to isolate the cause of my blues going slightly purple. Or for that matter, why relative colormetric wipes out shadow detail above a certain total area coverage.

Is a CMM strictly an equation? Or is it a little program that can intelligently map Lab values to a CMYK build of a printer?

Is the CMM even responsible for the symptoms I am describing?

For the purplish-blues, I would probably suspect the profile itself before the CMM. What software/version created the profile and what rendering intent are you using? For your shadow issue, are you using (can you use) black point compensation? I’ve had some profiles that showed all of the attributes you describe, but software updates generated much more pleasing results in this regard.

I’ve been building profiles with Profiler 4.72 and Profile Maker 5.03. Adjusting the Gamut size, GCR and separations through iterations can lessen the effect for a particular measurement data set, but not completely resolve the issue.

Calibrating a device is my approach to fixing the problem, but making itereations with ink and media is expensive. I’m hoping that the ICC workflow can handle and correct for some color casts of a particular device, but my experience has not been the case.