Re: gum prints from digital color sepations. (Since the topic has been brought up)

>
> I've got two tubes of "gamboge" M. Graham, and one is a different PY:
> (151), so there has been a change in formluation, but I don't think the
> yellow is as crucial as the magenta.

As I've remarked here a number of times, M. Graham stopped using PY110
some time back (two years, or three, maybe?); now their "gamboge" is a
mix of two pigments: PY151 and PO 62, benzimidazolone yellow and
benzimidazolone orange. I suspect the PO62 is used to deepen the hue of
the yellow to a more "gamboge" hue, as the PY151, which M. Graham
markets by itself as "azo yellow" is very light in tone and hue. (Of
course neither M. Graham's new version or their old version of "gamboge"
is actually gamboge, NY24, which is a fugitive pigment marketed only by
Winsor & Newton.)

At any rate, my personal sense is that the difference between the PY110
and the new pigment mixture is significant enough that I wouldn't think
of using the new M. Graham "gamboge" as a substitute for the old. For
one thing, neither the PY151 nor the PO 62 is as transparent as the
PY110, and in fact the PO62 is listed as opaque or semiopaque. When I
finish the M. Graham PY110 that I bought up when they discontinued the
pigment, I will switch to Daniel Smith's version of PY110.

Katharine Thayer
Received on Sat Oct 30 14:07:27 2004