Re: Pigment that makes gum insoluble w/o exposure?
Way back in the 1970s it seemed Windsor and Newton were safe bets for
gum.
Only the Windsor and newton Black thinned out to a true grey...
On Sep 24, 2007, at 4:48 PM, Judy Seigel wrote:
Chris Anerson wrote....
CUT
Anyway, on to red. I have never had a red spontaneously harden,
but I have found that students will tend to confuse two things--
stain and overexposure. I have no idea if either of these are your
case.
Two, is the ruby red a blue red? Offlist I got a question from
Michael Koch-Schulte about whether I had found reds to be faster
than other colors
etc.
Chris and all... beware of speaking in colors, that is, just by
color name. It's my experience that the brand of paint, as well as
the particular pigment (by number) and its source (manufactured?,
mined?, if so, where?, etc.) are crucial variables. Among others.
For instance, some makers include a so-called "dispersal agent" in
all or some of their tube colors. In my experience the dispersal
agent can very well disperse the pigment right down to China -- and
you can NEVER EVER make it clear.
Besides dispersal agents, some makes of color have fillers,
emulsifiers, thixotropic agents, foreign agents, real estate
agents, or other "improvements" in some or all of their colors....
I suspect that just naming "orange red" or "blue red" or like that,
especially from a Gum Authority such as Chris, could drive some of
the uninitiated to despair if not worse (eg., platinum).
Which is to say, to be on the safe side, a brand name should
probably be attached to such observations about paint behavior.
J.
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