Digital BW, The Print

> ... I was surprised to read Paul's comment about the EBONI 
> black being okay to swap into the system, because when I 
> asked the same question several people replied saying it 
> was not that simple ...

No guarantees here, but I think it's worth a try.

> I think the main reason was that the 'tone' of the eboni black 
> is not the same as the NK7 inks.

It is a relatively neutral black.  By the time the black ink comes in, we're
not that sensitive to slight tone differences.  It's just too dark down in
the deep shadows to see much.  The only tone differential problems I've seen
in these deep shadows are with very warm MK inks like the Epson MK.  In
general, a cooler black is simply going to look deeper.  That is clearly one
reason for Eboni's success.  The Epson MK often actually has a higher dmax,
but it almost always looks less black due to its warmer tone.

> Also some people said it has a different 'flow' property to the
> NK7's and might cause problems like clogging.

Lots of people are using it in Epson printers.  I don't hear much about
clogged Eboni jets.  The only problem I've found with it is that it does not
like to be in a system that has dye in it.

> Instead I found this solution, and get a Dmax of 1.65 now on 
> Hahn PhotoRag. Which is okay I guess.

OK, but still not great.

Be sure the black ink load is properly set via the Black Boost.  This can be
done by trial and error.  However, it's faster to use a 21-step test curve
and a straight line black curve with 100% load.  I use the first Calibration
print to set this.  However, you can do this later quickly by making a curve
that prints only the black ink at 100%.  In Curve Creator, make a straight
line black ink curve with the Default Ink Limit and Black Boost at 100.
(Leave the ink limit box by the black ink blank.)  In the Black (K) ink box
have "Load Curve."  Push the Curve button just to the right of the box.  Put
only (0,0) and (100,100) in the blank table as the end points of the curve.
Preview the curve to see that it is a straight line. Create the curve and
save it in the appropriate Profiles folder for your printer. Print a 21-step
test print and see where the black density is the highest -- a spectro or
even just a flatbed scanner can do this.  Use that 21-step number as the
Black Boost setting in your actual paper profile Black Boost box.  See if
that works.  It should have virtually no impact on the rest of the profile,
just taking the black ink limit to what is needed for the best dmax.  

As I've mentioned before, I'd use 2880 as the resolution.  If the profile is
for 1440, then that's a different problem.  You'll have to re-linearize the
curve to change it to 2880.  (What do Piezo QTR profiles use?)   

>When ready to print I convert my image from GG 2.2 to 
>Adobe RGB '98 in Photoshop and then go to IMAGE then 
>ADJUSTMENTS then SELECTIVE COLOUR. I then select the BLACK 
>channel, and just make the blacks +15 or so darker. Then 
>I convert back to Grey Gamma 2.2 and print as normal through QTR. 

This should not be necessary if the system has a good dmax and the Photoshop
levels and other usual editing tools have been appropriately used.  I
remember these workflow gimmicks from my Piezo days, but I think they are
not good substitutes for a decent dmax in the first place.  They will not
increase the dmax.  What they do is make sure you have enough of the image
at or close to 100% black so that the image has a good black "foundation."

One reason I now work at Gray Gamma 2.2 (and then apply a layer to convert
to the QTR or IJC straight line output) is that it compresses the black
tones.  What this does is give me a reserve of information in that hidden
deep shadow zone that I can utilize to fine tune the deep shadows without
having the image and file break down due to insufficient information or
steps left to work with down there.

> ... There was a Portfolio Black ink that Jon Cone used to make for 
> the old 4 Black system that gave a much better DMAX. Over 1.75 
> I think. It wasn't Pure Pigment though

It appears to have dye or some other similar fast-fading substance in it.
I'd avoid it for display prints.  As its name implies, I would use it only
for portfolios that are not going to be in the light for any extended
periods.  (Actually, I would simply not use it at all.)

Hope this helps.

Paul
www.PaulRoark.com