QTR-Quadtone RIP

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.
>> >> >>
>>
>