U of S | Mailing List Archive | alt-photo-process-l | Re: clearing dichromate stain

Re: clearing dichromate stain



On Mon, 8 Jan 2007, Katharine Thayer wrote:

.... Just for one rather trivial example, the statement that's attributed to Sil Horowitz, that in dichromate stain, the dichromate is "fully oxidized" and therefore inert. If Sil Horowitz said that, he's an idiot, but I'm completely comfortable saying that, because I don't think he is an idiot, I think it's much more reasonable to assume he was misquoted. The only way the first part could make sense is if he meant the yellow stain where the unreduced dichromate is trapped in the paper or the size, but in that case the second part wouldn't make sense; such a stain couldn't be considered inert. Anyone with any knowledge of the chemistry of the process would know that it's a nonsense statement as given, and would either check with Horowitz to find out what he really said, or at least drop the secondhand citation from the listing, since it's obviously a misstatement of fact.
Sil did say (rightly or wrongly in whatever terms -- should be in the archive for those who care) that it's not necessary to *clear* a gum print for the purpose of archivality. A similar point was made by Mike Ware, tho that was in terms of the dichromate being (reduced, deduced, traduced, whatever, to, as I recall, the trivalent, or inactive form, possibly chrome 3 (?))

But at my advanced age I've found the number of facts crammed into my brain tend to affect my vision (can't blink my eyes) and appetite (the gorge rises), and just generally impede performance. So I depend on a form of triage: Is this useful, possibly useful, or anyway *interesting *
information?

If not, omit.

Has anyone here ever heard of a gum print fading from dichromate stain?

I haven't.

In fact I've come across the statement in old articles that the dichromate stain is useful for adding density to an image -- & deliberately incurred by the author for that purpose. (If I could see into the future I'd have noted the reference, but if I could see into the future I'd be running the world & too busy for gum printing.)

We probably have 100 plus years of "gum literature." Has anyone else found a citation? My *guess* is that it's an association from silver printing -- as photographers found albumen and other silver media faded if not properly cleared, or washed, or fixed... so they felt they had to do something for gum. In fact in some early articles gum clearing is actually referred to as "fixing." (So it's psychological -- like "titrating" gum stain !!!)

Meanwhile, I lack sufficient time to run the world, gum print, monitor T-shirts, monitor this list, monitor diction, monitor my monitor, agitate where needed, and maintain my corporeal self. Whatever seems unessential (unless irresistibly delicious), as noted, gets cut. Clearing unseen "dichromate stain" and worrying about same are high on that list.

... there's no assurance that the second source isn't misinterpreting the information, as may have happened in this case.
No, Sil said it clearly and unequivocally... As for querying him, I wouldn't know where to contact him today, when, by my calculation, he'd be approximately 94 years old. Quite a few years ago Sil left the list for a while, saying there was something else he had to do. I don't know what that was... but we surely missed him, and in due course welcomed him back. But he didn't stay long. And didn't say goodby.

Did I say I miss him? ... in fact recently came across a little print I'd lent him for a talk he was giving, I'd labelled to point out that "contrary to common myth, gum can do fine detail."

Another pang.

Judy