QTR-Quadtone RIP

--- In QuadtoneRIP@yahoogroups.com, "dmwket" <dmw@...> wrote:
>
> Howard,
> The delay was so that I could do a profiling process for Brilliant
Museum Silver Gloss
> White using the process as I understand it based on your comments as
well as the
> documentation included with QTR.
>
>
> I am including a PDF document in which I describe the process.
Hopefully this will provide
> sufficent information for you to determine if the process is valid or,
if flawed what I
> should do to improve it.
>
> /Users/DMWMBP/Desktop/QTR Profiling 10.5.2.pdf
>
> I am happy to email you the word file if this would be more useful.
Let me know.
>
> I am happy to edit the process description and share it more widely
once I am sure it is
> valid.
>
> Regards,
> David
>
> --- In QuadtoneRIP@yahoogroups.com, Howard Shaw glassman@ wrote:
> >
> > Sounds like you might possibly be confusing the settings for ink
limit &
> > ink density?
> >
> > Density should alway be 100 for the black ink but the limit should
be
> > the level in the initial 100% calibration that gives you the best
dmax
> > (there are exceptions such as where the limit is set lower but
restored
> > with a higher black boost figure but don't worry about that at this
stage).
> >
> > Paste your qidf file into an email if you'd like me to have a look.
> >
> > regards
> > Howard
> >
> >
> > dmwket wrote:
> > > Howard,
> > > Thanks for the information.
> > > I found that when I tried to set the ink limit below 100% for the
black, then the step
> wedge
> > > did not print at all.
> > >
> > > For example, if the best Dmax was the 95% wedge and I set 95 as
the black limit, then
> > > when printing the step wedge, the 100% wedge was just an outline.
Also, all the
> numeric
> > > text next to the steps were also just an outline.
> > >
> > > That's what led me to the conclusion that the black ink limit had
to be set to 100 in
> all
> > > cases and that the LK limit was used to set the point when K ink
was used rather than
> the
> > > LK ink.
> > >
> > > There are two or more places in the profile text file that have
ink limit setting.
> Perhaps
> > > this is what is causing me the confusion.
> > >
> > > Which settings are used to limit the total black ink flow to
optimize Dmax?
> > >
> > > thanks again for your insights.
> > >
> > > David
> > >
> > > --- In QuadtoneRIP@yahoogroups.com, Howard Shaw <glassman@> wrote:
> > >>
> > >> David
> > >>
> > >> No, the calibration process should be done for each
printer/ink/paper
> > >> combination. Different papers can take different amounts of ink
and the
> > >> main purpose of the calibration is to guage the level of black
ink which
> > >> provides the best dmax as well as the 'crossover' points for the
black &
> > >> grey inks.
> > >>
> > >> Printing the initial 100% calibration will give you the full
range from
> > >> 5%-100% coverage. Dmax can actually decline with overinking and
the best
> > >> dmax patch will almost certainly not be the 100% one.
> > >>
> > >> My experience shows that, even using the Media Type of Matte
Paper,
> > >> there are no papers, matt or gloss, that can take anything like
the
> > >> amount of ink deposited in the 100% patch at the 100% calibration
limit
> > >> at 2880dpi. The Matte paper setting therefore provides more than
enough
> > >> latitude in terms of quantity of ink deposited.
> > >>
> > >> Media Type may determine other factors (?platen gap ?drop size)
that
> > >> might be factors but the evidence is inconclusive. Hopefully more
people
> > >> will reply to the other David's thread in this regard.
> > >>
> > >> regards
> > >> Howard
> > >>
> > >> --
> > >> Howard Shaw
> > >> www.howardshaw.org
> > >>
> > >> dmwket wrote:
> > >> > Howard,
> > >> > It is my understanding from reading the material that the Ink
Separation
> calibration is
> > > a
> > >> > printer specific, not paper specific calibration.
> > >> >
> > >> > I did that calibration before starting the per paper profiling
I described.
> > >> >
> > >> > It is important to remember that that has to be accomplished as
well. Thanks for
> > > pointing
> > >> > it out.
> > >> >
> > >> > What drove me to doing the detailed profiling I described here
is the lack of Dmax
> > > with
> > >> > the default matte paper selection even after doing the
Separation calibration.
> > >> >
> > >> > Regards,
> > >> > David
> > >> >
> > >> >
> > >> > --- In QuadtoneRIP@yahoogroups.com, Howard Shaw <glassman@>
wrote:
> > >> >>
> > >> >> This method may work if the best black ink density for the new
paper
> > >> >> matches that of the paper whose existing profile you use.
> > >> >>
> > >> >> However a better way to optimise dmax and take out some of the
guesswork
> > >> >> is to standardise on one paper setting & resolution and print
one of the
> > >> >> ink separation tifs in calibration mode. See the file
'QuadToneRIP User
> > >> >> Guide.pdf' in the qtr folder for more details.
> > >> >>
> > >> >> Howard
> > >> >>
> > >> >>
> > >> >> dmwket wrote:
> > >> >> > Alan,
> > >> >> > Linearization is done on a per paper basis.
> > >> >> >
> > >> >> > It is the profile used by QTR for that paper.
> > >> >> >
> > >> >> > Based on experimentation and reading here on this forum I
arrived at the
> > > following
> > >> >> > process;
> > >> >> >
> > >> >> > 1) Select an existing profile text file that approximates
the paper you want to
> > > profile
> > >> > and
> > >> >> > delete the Linearization line at the end of the file and
save with a unique
> name.
> > >> >> >
> > >> >> > 2) find the best Dmax by printing 100% black squares with
several paper
> settings
> > > i.e.
> > >> >> > Premium Gloss Photo Paper, Premium Luster Photo Paper, etc.
at 1440 as well
> as
> > >> > 2880
> > >> >> > using the file you created in 1 for the curve.
> > >> >> >
> > >> >> > I positioned the ink swatch on the paper by clicking center
image off and then
> > > setting
> > >> > a
> > >> >> > margin to create a row of swatches at the various setting.
> > >> >> >
> > >> >> > These samples are all printed with No Color Management set
in the printer
> dialog.
> > >> >> >
> > >> >> > This is tedious but important. I let the samples dry for
about 2 hours before
> > > reading
> > >> > them
> > >> >> > with my Spyder Spectrometer.
> > >> >> >
> > >> >> > 3) Once the best Dmax paper, resolution setting is found.
use that paper and
> > >> > resolution to
> > >> >> > print the 21 X 4 step wedge using the curve created in 1.
> > >> >> >
> > >> >> > 4) Let the test print dry for a minimum 2 hours, over night
is optimum, then
> read
> > > it
> > >> > and do
> > >> >> > the linearization.
> > >> >> >
> > >> >> > 5) Copy the Linearization line from the text file and paste
it into the file you
> made
> > > in
> > >> > 1
> > >> >> > above and save the file as your curve file for the paper.
> > >> >> >
> > >> >> > 6) Copy the file into the printer profiles folder and
"install the printer".
> > >> >> >
> > >> >> > 7) Once the curve is installed I save a preset for QTR that
has the paper
> selection,
> > >> >> > resolution setting and curve. I name the preset to reflect
what paper it is to
> > > simplify
> > >> > my
> > >> >> > printing.
> > >> >> >
> > >> >> >
> > >> >> > Trust this helps.
> > >> >> >
> > >> >> > There may be a better way to do this that someone more
experienced can
> offer.
> > >> >> >
> > >> >> > Have fun learning QTR --- the B&W prints it produces are
great.
> > >> >> >
> > >> >> > Regards,
> > >> >> > David
> > >> >> >
> > >> >> > --- In QuadtoneRIP@yahoogroups.com, "handyman856" <avr@>
wrote:
> > >> >> >>
> > >> >> >> Is linearization done on a 'per printer' basis, done once
with any
> > >> >> >> paper for a given printer, or is done 'per paper', and part
of the
> > >> >> >> profiling process of each paper?
> > >> >> >>
> > >> >> >> =Alan R.
> > >> >> >>
> > >>
> > >
> >
>