Digital BW, The Print

Thank you very much Mr.Roark for the Polar Matte profile. The minute I'll stop fighting with the installation of QTRip over my network, I'll try it for sure. I'll see also what I can do with the ink limit so I can get better definition in the blacks.

Thanks again

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Paul Roark <roark.paul@...> wrote:
>
> Pete Bergstrom <petebergstrom@...> wrote:
> > ... I found is that with a flatbed scanner
> > (Epson 4870 in my case) I could calibrate a new set of EB6 inks (my own
> > dilution ratios) in about 4 prints, ...
> 
> > ..., the first step is to choose an ink limit for the black.
> > You can efficiently do this with a 21-step image and QTR's
> > calibration mode. ...
> 
> Yes.
> 
> > I ended up with about 25-35%.
> 
> I made a profile for Red River Polar Matte and found the K ink limit to be 35.
> 
> The new QTR profile as well as an ICC for this paper are now in
> http://www.paulroark.com/BW-Info/1400-Eb6-Profiles.zip .
> 
> 
> > Next, using this overall ink limit, I printed the calibration mode image
> > that QTR provides. I let it dry, then scanned it (RGB). Using (in my case)
> > Photoshop Elements, I then measured the "relative density" reading of each
> > patch (green channel, 5x5 pixel sample) ...
> 
> I usually find that the lighter inks can handle a higher ink limit
> than the denser black ink.  As such, once you find the K ink limit,
> you can set that as the default and leave all the other ink limit
> boxes blank so that they use the default/K ink limit.  Then scanning
> the entire second Calibration Mode print that was made at that default
> ink limit makes finding the relative densities in Photoshop, using the
> eyedropper, a very easy approach.  Hopefully a scanner is going to be
> consistent enough that you could simply measure the 100% patch for
> each lighter ink with the eyedropper and then see where that density
> occurs on the black ink 21-step.  That would give you the relative
> densities for that same default ink limit.
> 
> The QTR profile for Red River Polar Matte used this approach and
> linearized quite well.  It did need linearization, but this is normal.
> 
> For the ICC I used the general NCA correction curve that is in the Zip
> file.  With newer software, ICCs always use the driver set to ICM/OFF
> (No Color Adjustment).  With that setting, the 21-step test print
> makes a curve that has too steep a step between 95% and 100%.  That is
> why the NCA correction curve, which is generic, helps with the
> process.  It is embedded in the ICC by dropping it into Create ICC-RGB
> along with the Lab L data.
> 
> Paul
> www.PaulRoark.com
>