Digital BW, The Print

Hello Mitch,

Thanks for the good report.  I'm using a 2400 with MK on matte papers
in ABW mode, and there are some things in your report that are
different from my experience.


>The Epson Driver for the K3 printers in Advanced B&W mode puts  
>down a light-gray rectangle...it means that the "paper white" is 
>not as bright as the original paper, which is also true for the 
>highlights in general

I have never noticed anything like this rectangle in my prints.  In
fact, I have been pleasantly surprised that the 2400/K3 prints have
more luminance than I was used to seeing in full ink prints.  I've
been printing mostly with BO until this, and one of the things I love
about that approach is its wonderful luminance caused by the paper
white that shows between the dots, so this is one area where I have
been particularly attentive.  

In analyzing my K3 prints with a loupe, I saw first that the ink dots,
while tiny, are distinct, and further that there is what appears to be
uncoated paper between them in the highlights.  One of my complaints
about full ink systems in the past has been the opaque look caused by
what seemed to be a thin coating of nearly clear ink over the paper
between the dots in the highlights, which has a dulling effect.  So my
impression is that 2400/K3 is more luminous than many other full ink
systems.  They have a good glow to them and I've been very pleased. 
One of my samples has bright sky and cloud reflections on water, which
is very delicate and high key.  It is right on the edge of density,
close to paper white.  It can make or break the print and the 2400
handles it beautifully.  So my over all impression is that K3 is
extremely good at luminance and holding subtle tonal gradations.

I'm wondering if what you're seeing is the result of some kind of
driver setting.  There is something in ABW mode called "Highlight
Point Shift" which is defined in the Docs as"

 "Select this check box to add a little more ink to white 
 areas to give it a glossy look."

...I think this is for avoiding gloss differential on glossy papers,
and I'm wondering if this might be what's causing the rectangle (I've
never used it, so I'm just guessing). 


>The ImagePrint print has more shadow detail than the one made with  
>the Epson Driver Advanced B&W mode. 

ABW settings are also important here.  There is a "Tone" picklist with
5 choices from "Light" through "Darkest", and it turns out that this
does more than an even change of the over all density.  It turns out
that the actual contrast curve is modified so that the shadow zones
are increasingly compressed as the setting gets darker.  This was
demonstrated clearly in a set of 5 prints someone sent me recently. 
They were of the identical image printed at each Tone setting, and
included a step wedge on each one.  The low end compression is clearly
seen to increase as the settings get darker, to the point where the
last few steps on the "Darkest" one are nearly indistinguishable.  So
my default setting is always "Light", and I'm getting excellent shadow
separation.  For some reason Epson's default setting is "Darker", so
we must be careful to put this where we want it.


>Moreover, the blacks on the K3 print were slightly darker than  
>on the Ultrachrome print

K3 is definitely a different technology.  One thing that seems to be
emerging from reports is that it's dmax varies significantly than
other inks on certain papers.  A recent thread here discussed these
differences on Epson's VFA paper.  K3 dmax on VFA is superior to some
other papers, but with UC and MIS inks the reverse was true.  So it
seems we're dealing with a very different technology with K3 and some
of the old rules are being broken.


Regards,
Clayton


Info on black and white digital printing at    
http://www.cjcom.net/digiprnarts.htm