Re: Gum Pigments

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From: Judy Seigel (jseigel@panix.com)
Date: 07/28/03-06:13:18 PM Z


On Fri, 25 Jul 2003, Christina Z. Anderson wrote:
> .... Throughout
> history the "baddies" were the chromium pigments, said to interfere with the
> process, Prussian blue being incompatible with the cadmiums (which does
> fade), aniline colors which would stain, tube pigments whose fillers would
> interfere with the process or create staining, Emerald green is poisonous
> (as if we are going to drink our pigment) etc. So, yes, this was a myth I
> totally believed in, and said myth was debunked on this list time and time
> again over the last 6 months.

There's also a good chance that many pigments sold with those names are
now other formulations...If you look up many of them (try terra verte, for
instance) you can find they're something else.

> Contrary to Judy and Jack's opinion about old books being wrong,

I don't think they're necessarily WRONG so much as not applicable across
the board.... Or applying to only those methods and those particular
ingredients. For instance, NOT the ratio of gum to pigment, NOT the brand
of paint, not whichever bichromate, or any of those topics which seem to
obsess this list, but for instance IME a crucial variable is the
particular gum. I find with everything else identical the particular gum
arabic is often a MAJOR MAJOR variable. (I've mentioned the tests I did
with another lister, who used Photog Formulary gum, while I used RBG...
everything otherwise identical. He was getting staining that I was not.
But when we changed one ingredient (I forget now which, maybe the pigment)
I got staining he didn't.

So I can't help noticing that tho all of Stuart M's findings and
techniques are intriguing-- he doesn't name his gum.I wonder if they'll be
the same with different gums...

As for yesteryear -- most papers, even if they have the same name today,
are different... as Liam mentioned in P-F #8,nearly all now have buffers
added -- at the very least.

> intentionally or not, I find that most errors or myths about gum printing
> have been in the latter 20 years of the *last* century, and NOT during the
> end of the 1800's and early 1900's. In my opinion that is because during
> that time period of about 30 years around the turn of 1900, many many people
> were actually DOING gum and madly talking about it! Instead of doing other
> alt processes, dabbling in gum, and not taking the time to waste paper--just
> for the hell of it.

Following the books as well as I can, I find the myths originated with ---
sorry guys -- Paul Anderson. I have to get ahold of his 1913 series in
American Photography on Gum Printing, but if it's the same as his series
in The Camera in 1935, several myths began there -- picked up by, sorry
Chris, Crawford then Scopick, and from there to the world.... but more on
this later...

> And in reference to gritty imagery vs. fine detail, ya do gum bad, ya get
> grit; ya do it right, ya get fine detail. It is not hard to get fine
> detail, even tho this myth is promoted time and time again.

When I've solved some other crises in hand I'll address a few of these
assumptions, plus some that apparently Stuart began with, but for now--
what's the matter with grit? And you could also get very fine detail with
the look of grit !! So, could we please not define "the best" gum as the
closest imitation of platinum? Yuck. Etc.

Judy


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