Re: Scanning pigment stain

From: Judy Seigel ^lt;[email protected]>
Date: 04/21/04-09:37:56 PM Z
Message-id: <>

> KT: This is interesting, but hardly devastating; as I've already said
> more than once, my findings differ on this point, and as you rightly
> predicted, I can hardly find this one data point convincing against all
> my experience and observation and my own more extensive tests, which did
> address the question of whether the Anderson test is relevant to gum
> printing practice by directly comparing progressively increasing
> pigment/gum ratios with and without sensitizer/exposure, and found no
> difference.

"Devastating"??... Being wrong is "devastating"? That's NOT a good way to
do science.

And speaking of science, I think it was Karl Popper who said, all you need
to prove that not all swans are white is one black swan. I've seen flocks
& flocks of black swans...

I also find the investment -- of Katharine apparently, but others also --
in "testing" gum bichromate photography with no bichromate and no
photography... odd. It's not easier and obviously less conclusive. The
"response" at hand had so many non sequiturs and irrelevancies it's
pointless to "reply" -- but overall: yes, yes, more pigment can show a
greater *absolute* amount of staining, but Anderson's claim was a special
threshhold. And no, I don't say other printers weren't concerned with
pigment stain, Demachy or whoever. I say, it rated *at best* a paragraph
or two.

Stain became a MAJOR ISSUE for Anderson because he used 100% sodium
dichromate solution 2 parts, to 1 part gum. Other printers used 5%
dichromate, often one part to two or even three parts gum.

His greater concentration of dichromate made staining the hallmark of
Anderson's gum career. His "system" got him into the canon, and, "When the
old-process revival began in the 1970s, authors had little or no living
tradition to draw on, especially for gum. Anderson was there in the canon,
waiting for them." ["Engineering Gum Bichromate (While falling into the
Photo Canon)" in P-F #9, now -- ta dah !-- at the printer.]

Received on Wed Apr 21 21:38:18 2004

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