QTR-Quadtone RIP

Getting the PDF file into this thread has proved beyond my skill.
I have uploaded it to the files\documents section of the group.

it is titled QTR Profiling 10.5.2.

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.
> >> >> >>
> >>
> >
>