Digital BW, The Print

Bernd,

You wrote:

>... IRIS prints, they did not only warm up, but
>had different color shiftings in different areas of the image.

That's not good at all.  At least our inkjets seem to warm uniformly.

>...I'm a silver printer too. I used to print on Agfa
>Multicontrast Classic (Baryt). It is warm-toned in neutral
>developers, but can be much warmer than Piezo in warmtone developers.

I used Dektol with it for some time.  I found, however, that I preferred the
cooler Kodak Polymax Fine Art.  When toned just a few minutes in selenium
1:19, the print ends up very neutral.  My scanner shows the print to be
about 1 unit warm (yellow).

>I\ufffdm very curious whether I will switch to cooler tones with your
>variable inks I ordered for my 1270. Maybe I\ufffdll fall in love with the
>cooler tones if I see my industrial landscapes printed with MIS inks?!

I think just due to the novelty of it I was printing quite cool at first.
I've now backed off to what I call neutral -- it's actually 4 units cool
(blue).  (That is, the Blue channel of the RGB readings on my scanner is 4
units above the Red channel reading.  I'll have to do more homework to
understand the HSB model.)  I have the "neutral" tone set there anticipating
some warming.  That tone seems to look very good hanging next to my Kodak
Polymax prints.

>Paul, what do you mean with dyes/pigments? Doesn\ufffdt Jon Cone claim his
>inks are pure carbon pigments?? Or did I MISunderstand something?

Jon acknowledges that there are some dyes in the mix.  All of these
pigmented inksets have some "dyes" in them.  However, he has declined to
give us any specific percentage of his mix that is dye.

Bob Zeiss at MIS has said that MIS inks are about .5% dye.  He explains that
all the desktop pigments are carbon based.  (Some large format, less
photographic printers use large particles of pure pigment.  However, those
pigments cannot, apparently, be ground fine enough for the
desktop/photo-realistic printers, and the gamut is not very good.)  Because
carbon is a warm brown color, the carbon particles are then coated with a
colorant -- black for the black, color for the color.  This is what Bob
calls the "dyes" in his mix.  And, I've gotten the impression this is the
only dye in MIS.

Some pigmented inksets, however, actually have some dyes in solution that
are not just a coating on the carbon particle.  I think the blackness of
Generations Enhanced black is achieved this way.  I think Piezo is also in
this group.

If you take a drop of Piezo magenta-position gray, for example, and put it
on a Kleenex or paper towel so that it will spread, you will see the colors
separate.  (I remember doing chromatography in high school chemistry -- the
same principle, I'd guess.)  The Piezo ink splotch will end up looking very
dark in the center, but it will have a fringe of what looks green-blue to
me.  I think what this might be showing is the separation of the dye from
the pigment.  I would expect the dye to migrate further through the paper.

If you take a drop of the MIS variable-tone/mix magenta-position ink, which
is the same density as the Piezo magenta-position gray, and you do the same
thing, you do not get a color fringe.  Maybe this is because MIS inks do not
have color dyes in them.

Keep in mind that I'm not a chemist with any sophisticated method of testing
all these inks.  I'm just summarizing my understanding of what is going on
based on what I've been told, read, and observed in my own experimenting.
Of course, what I've been told by many is not necessarily consistent -- nor
are all of my own experiments -- so I always reserve the right to say I was
wrong.

Paul
http://www.PaulRoark.com