Digital BW, The Print

Clayton,

>>I've also been curious to experiment with a slightly cooled light
>>black.  I'm concerned a bit with the very warm nature of the
>>existing light black inks (both MIS and Epson).

>How are these inks being cooled?  I've never seen
>anything about that.

I use color pigments to tone the carbon black inks.  The light and photo
black inks make great base grays when diluted.  Then it's a matter of
finding a compatible color pig that can do the job best.  So far, the MIS
7600 pigs seem to be the best.  My tests with the Epson Archival pigs have
been very disappointing.  It's probably not that the pigments are inherently
less stable, but more likely that the MIS 7600 base is incompatible with the
Epson coated pigments.

>Do the coolants seem to alter the fade/shift properties any?

Yes.  That is one of the issues.  In fact, the FS-N is "non-warming" because
I added just a little fast-fading yellow and then balanced that with very
lightfast cyan & relatively lightfast magenta pigs.  It was what I called a
"counter-shift" approach to the problem.

Now we have so much better base black pigment, that the warming issue is
very different.  The carbon pigs do yellow a bit, but that yellowing is not
from a drop in cyan or magenta, but an actual increase in yellow
reflectance -- the density is actually increasing initially with light
exposure.

Some of the things I'm trying to do with the current inkset is keep one
"color" spot "pure carbon."  (It appears that the cyan position is best for
that.  I tried the magenta spot and, rather unexpectedly, the driver and
sliders reacted differently -- and with much less satisfying results.)  I
want that carbon ink to be pure so that I can print with RGB PS curves a
pure carbon image for maximum longevity.

The color pigs are getting very good, but they are still, as far as I can
tell, not as good as the "carbon" (or whatever the black pigs are made of).
Two years ago the yellow was the weakling.  Then that was improved
substantially.  The cyan has been the rock solid one in fade tests, but,
interestingly, Cone's tests may indicate Epson in the UC inkset has found a
super-stable magenta.  To be frank, one reason I like the "selenium" tone is
that the slightly raised magenta will help offset what I think will be a
gradual fading of that pigment (read green shift).

So, there is shifting that is going to happen.  Hopefully its so far down
the road that we don't have to worry much.  However, whether the inks would
be better if I used a counter-shift strategy with even the current
generation of pigs is an open question.

Paul
http://www.PaulRoark.com