QTR-Quadtone RIP

Thanks Roy & Olivier,

Little by little I think I'm getting this and am close to grasping the
big picture.

Roy, I read through the entire thread that you had linked to and it
cleared up quite a bit for me. However, I'm hoping you can answer a
couple questions, as I'm still a little fuzzy on a few details. If I
understand clearly what I've read, then there have been two main
workflows ending with QTR.

The first (and apparently outdated?) process, completely bypassed any
color management system and sent the file straight to QTR sans
conversion, as per the printing instructions in the tutorial. So, the
calibration & characterization/profiling of any ink/paper set were
being combined in the QTR curves. And, any particular bumps in the
output were taken care of by further manipulating the curves or
through correction layers or some similar tactic.

Now however, it appears that the linearization is only meant to
calibrate the output and any characterization/profiling is being done
via QTR-Create-ICC, essentially leading to the same type of process as
a color managed workflow.

While I can't find the quote, I recently read something regarding
color management that stated, ideally calibration and linearization
would be all that was needed to color manage a device, but since there
are still irregularities in the output, profiling is necessary.

If the above statement is true, then am I right in coming to the
conclusion that using profiles in addition to the QTR curves is
optional, as long as one is willing to tweak their linearization
curves or use corrective layers in order to get their desired output?

Also, if working with profiles, since the calibration is largely
dependent on the particular paper being used, would one have to create
a set of QTR curves for each paper as well as create a profile or in
the case of differing tonal output, multiple profiles per paper?

What exactly is the target performance that is desired, when
linearizing your output, re: the "ideal" densities? Am I correct in
assuming that the densities are meant to correspond to the human
visual response to changes in value, or are they more an arbitrary
division of densities based on mathematical/mechanical efficiency?

Thanks again in advance,

Eric
www.ericashworth.net



--- In QuadtoneRIP@yahoogroups.com, "Roy Harrington" <roy@h...> wrote:
> --- In QuadtoneRIP@yahoogroups.com, Roy Harrington <roy@h...> wrote:
> > On another group I wrote a fair amount about the linearization, icc 
> > profiling, etc.
> > I'm not sure I addressed all you questions but I think it will help a 
> > lot.
> > 
> > See:
> >
http://groups.yahoo.com/group/DigitalBlackandWhiteThePrint/message/68052
> > 
> > Roy
> > 
> 
> I decided to load the info into the Files section of this group.
> 
> See:   ICC Info.txt
> 
> Roy