Digital BW, The Print

Steadman,

You wrote:


>...I am impressed that the MIS VM inks offer an interesting alternative for
>standard quadtone BW printing.  And for now at least, it seems to be
>an inexpensive inkset for printers who want cool tones from one cart/cis.

>I understand that one of the ink positions (magenta) is the Cool Tone Toner
>(and contains some blue dye based "toning" inks).

On 4-ink printers the toner is in the yellow position.  On 6-ink printers
the toner is in the magenta position.

The toner is composed of pigments -- not dyes.  I use MIS archival color,
that has been rated to at least 50 years by RIT.

>... question:  If you want a warm toned print, using
>the warm curve, would that not make your print a
>"tritone" instead of a "quadtone" in reality?

What first got me thinking about a variable-tone inkset was Jon Cone's
statements that only 3 inks are needed to make a smooth-toned B&W.  But,
since I always have to see for myself, I first wrote a curve that printed
the Piezo inkset through the Epson driver but totally eliminated the
lightest gray ink from the highlights.  When I compared test strips with
prints that had the lightest gray ink there, I could see no differences
between the test strips.  That is, the second-lightest gray ink in the Piezo
inkset could print a visually dotless highlight.  The lightest gray ink was
superfluous.

So, it is correct that for the most part the warm curve prints with three
inks in most of the curve.  (The toner is still needed to control in black
ink, but is so dilute compared to that ink that it doesn't have much visual
impact.)

>Also, I am no ink chemist, but I always had the impression
>that cyan dye inks were subject to fading more readily
>than black inks (dye or pigment).

The cyan pigment (not dye) that is used is even more light fast than the
black pigment ink.  It's an amazing ink and is probably why the cooler the
print is, the more lightfast it seems to be.  See the MIS RIT results at

http://www.inksupply.com/index.cfm?source=html/rit.html

I've done accelerated fade testing with a florescent light fader, and Jerry
Olson has done south window tests.  I use Archival Matte as my standard
paper for these test.  The tests all seem to show that the variable-tone
inksets are more stable than Piezo inkset.  In straight Piezo v. standard
MIS accelerated fade testing in my florescent light fader, the Piezo test
strip faded fully 65% more than the MIS test strip after 300 hours of
exposure.  I always put comparison test strips in the fader together so as
to eliminate other variables that could throw off comparisons between
different test cycles.

So, no guarantees that the MIS VM inkset will last for any number of years,
but it is essentially the MIS archival inkset that was tested to 50 years.
The weak link in that test was the yellow, and the MIS VM inkset has no
yellow pigment ink in it.  Moreover, the black ink that MIS uses for the
base of the gray inks is more lightfast than the Generations black that has
been tested to 75 years.

I feel confident that the MIS VM inkset has significantly less dye in it
than the Piezo inkset or the Generations inkset.  All of the pigments are
carbon that is coated with a colorant.  MIS, perhaps being too conservative,
called this coating a "dye."  However, this is not a dye in solution, and
those are the ones that appear to be the problem.  The pigment coating is on
all the desktop pigments -- even the black inks.  The extra dyes that I'm
concerned with are those that are put into the solution and are not part of
the pigment particle.  There are none of those in the MIS VM inkset.

I beleive this MIS VM inkset should be as good as the current pigment
technology allows, and that appears to be very good compared to any other
inkjet output.  At some point I'll fade-test it against the Epson 2000P
inkset and see how it does.

Paul
http://www.PaulRoark.com