Re: Gum Pigments

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From: Judy Seigel (jseigel@panix.com)
Date: 07/31/03-01:23:04 AM Z


On Mon, 28 Jul 2003, Christina Z. Anderson wrote:>
> Judy,
> I don't know how much clearer I can be on this subject but here goes
> one more try:
>
> DRUM ROLL: Paul Anderson did not invent pigment stain.
>
> The pigment stain test was in the literature long before: Demachy and
> Maskell as I have said months ago on this list, in *1898*; Warren's *1898*
> book, Richards' *1905* book, the *1905* Practical Photographer Series 18, is
> that enough to vindicate Paul Anderson? Certainly on other points he may be
> wrong--don't have time at the moment, nor interest, to address those.

Hey Christina, I'll see you and raise you two drum rolls !!! I have
several of the books you mention and others-- as I'm sure you do as well
-- tho I have never seen the Gum-Pigment Ratio Test before Anderson, who
passed it to Henney and Dudley, who passed it to Crawford, who passed it
to Scopick, and so forth...

However, my point isn't that Anderson INVENTED pigment stain, or even
necessarily that test (tho a quick scan of the Practical Photog book
brings up nothing) but that if you follow the commentary and the
procedures, he was the one made a fetish of it. For instance, Franklin
Jordan published "Photographic Control Processes" about the same time as
Anderson's "Pictorial Photography." Jordan mentions pigment stain in one
sentence in passing. Jordan was the more important & better known figure
at the time. The reason Anderson was enshrined in history more than Jordan
I will go into later, but my point here is that Anderson's methods MADE
PIGMENT STAIN WORSE, raising it from a possible hazard to a near-certain
blight.

That is, he printed with 100% SODIUM DICHROMATE !!! Which he used two
parts sensitizer to one part gum or even 3 to one. Most gum printers
(including Demachy et al) used 5 or 10% potassium dichromate one part to 2
or 3 parts gum ! And if anything could cause pigment stain to rise to the
top of the glitch list it would be that VERY HIGH RATIO of DICHROMATE --
I'm not in a state to do the math now but I've done it in the past & would
guess Anderson printed with about 100 times the dichromate of the others.

Thus it seems he was causing the problem (which others sometimes
mentioned, sometimes not, but didn't obsess about) -- and so he came up
with this Gum Pigment Ratio Test to not let you use more than the faintest
whisper of pigment, which of course would have a very hard time staining
or for that matter coloring anything much. So you had to use a LOT of pale
coats. Not only did the paper get abraded, the sizing wear off, but the
register tended to get a bit off with all those coats (Anderson mentioned
as many as 17, and the custom of the time did NOT include preshrinking),
with the result that detail and sharpness were lost.

I have a selection of quotes on the topic going back to about 1906, which
I will share, but now it's 3:10 AM & the roofer is coming about 8 AM
(roofers do that, I think it's part of their work ethic -- ours is also a
vegetarian and doesn't wear leather...but great on roofs, or is that
rooves?).

I will continue this topic when time permiits. I think it's important to
understanding gum. It's also full of surprises.

cheers,

Judy


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