From: Christina Z. Anderson (zphoto@montana.net)
Date: 08/02/03-10:24:06 AM Z
<Dick said>One need not overly
> complicate the gum process and get all tangled up in the issue of pigment
> staining.
Dick,
I think Clay's talking about dark reaction, not pigment stain.
Certainly sizing would take care of any pigment stain, but if you DON'T want
to size (like some of us, and like many of the gum printers today and of
old) this is more of an issue.
> I too have my treasured copy of Kosar and have noted the section that
talks
> about incompatible pigments with chromium. The main one was is
ultramarine.
What page is the ultramarine or chromium comment on? What edition? I have
not run across that pigment name mentioned, and am interested if it is
because when I mix this color into gum it gives off a really smelly smell.
However, it still works fine, and without staining, although I find it a
weaker color as you have, below. Kosar mentions the comment about pigment
incompatibility but doesn't say which are incompatible, not even chromium.
Scopick repeats this statement about chromium pigments and sources Blacklow.
Blacklow doesn't source. So I am curious.
Chris
> Despite Kosars references I did not see any degradation of ultramarine
with
> chromium in carbon printing. It is quite transparent compared to thalo and
> uses up a ton of pigment, an issue when you are coating 75 sq feet at a
time.
>
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