From: Judy Seigel (jseigel@panix.com)
Date: 03/17/03-02:00:35 AM Z
On Sat, 15 Mar 2003, Christina Z. Anderson wrote:
> I want to go thru the D. Smith catalog
> and see which pigments are labeled staining and which are not, and see how
> that all relates. OHHHH, so much to test, so little time....
> Chris
christina... strangely or not, the "staining" category doesn't apply to
gum printing, or not that I've ever been able to detect. I don't think
I've begun to lose memory at a faster pace than usual, though of course
that's possible, but alas I can't recall with perfect precision the
explanation of the category "staining" as given by a Winsor Newton rep at
College Art (sometime in February). Still, I'll stick my neck out and
cobble together what I do recall....
I'd already noticed lack of connection with the manufacturer's designation
in my own printing -- I've found that *staining* when it happens is
due to some dumb mistake -- old emulsion, too hot, too humid, bad paper,
bad size -- or like that. But the explanation from the W-N lady of those
categories in *watercolor painting* was as I recall that the stainers are
colors made from the old mineral pigments. The particles are fairly large
and irregular & roll around and get stuck in the paper fibers. The
non-staining are the new synthetic colors with much finer particles,
"almost like dye." I put that in quotes because I remember that
particular phrase from a rapid-fire discussion as the exhibition hall was
about to close.
But apparently Winsor Newton has phone tech support. Call them -- and say
you're an art teacher --- and you can probably get the story straight.
They also do some kind of class about paint & pigment in schools. And have
a number of interesting new materials...
But we don't get a lot of correlation of gum behavior with watercolor
behavior (that was the false premise of Scopick's "medium" for dry
pigment). In watercolor, the paint is thinned I mean really *thinned* with
water until it's just the palest tint.... and the gum arabic in those
veils and washes is almost non existent. In gum printing, even in the
zimmerman process, a much more robust paint-gum mix is used. The half
tones and highlights are achieved by removing the unhardened part, not by
thinning the paint with water. So even with little or no gum added as in
Zimmerman, the
pigment remains embedded in gum.
So I'd bet a nickle that those "staining" colors aren't extremely relevant
for our purposes--- tho it does occur to me to wonder if WN uses the same
"pigments" as DS...
J.
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