QTR-Quadtone RIP

"mozar94" <sylvain@...> wrote:

> I started printing on Hahnmühle Photo Rag, with P. Roark's
> profiles. Great results indeed.
> Now, I would like to try on Hahnmühle Bamboo, and perhaps
> one baryta as well (Hahnmühle Fine Art Baryta or Photo Rag Baryta).
>
> To make the profile for those papers, is it worth starting
> the job from scratch or can one just linearize from the
> PhotoRag profile? This should help to save sheets...

My preveious response probably confused a few things.  I so often use Create ICC-RGB that I was thinking of that with respect to whether curves can be easily re-linearized for different papers.  With that approach I've recently found that all the matte papers I've tried seem to be within linearization range for the monotone Eboni/Carbon-6 inkset curves I've made.

For inksets that use color pigments in them, I think there is more variability in the print tones. The different pigment types appear to be absorbed differently by the papers. I've helped people with making QTR ICCs for the old UT7 inkset, for example, and I find the color consistency is the main problem with simply re-linearizing an old profile for a new paper.

With QTR rip, Dario is correct, the ink limits often need changing.  What I like to do there is  use a relatively low default ink limit  for the midtones and use Black Boost to optimize the dmax.  Then there is also more portability among papers -- set the black boost based on a 21-step BO test and then see if the full curve is close.  I always graph the results with Excel to see if the pre-linearization curve looks to be within range.

Paul
www.PaulRoark.com