From: Wayde Allen (email@example.com)
Date: 05/19/00-09:44:48 AM Z
On Thu, 18 May 2000, Jeffrey D. Mathias wrote:
> Wayde Allen wrote:
> > ... Platinum is also a chemical catalyst and could cause rapid aging of the
> > support paper.
> Please explain this.
> The platinum left in the paper is metallic platinum, a nobel metal.
> There are many catalysts incorporating platinum and large molecular
> surface areas, but I have never known this scenario you have sited.
I've seen several references to the platinum catalyzed aging of acidic
papers in contact with the platinum image. I can't remember some of the
sources off the top of my head though. I think the Kodak book
James M. Reilly, Care and identification of 19th-century photographic
prints ([Rochester, N.Y.]: Eastman Kodak, 1986)
talks about this effect, but I forgot to look it up last night. At any
rate, this would be a good place to check.
With some difficulty I did locate a web reference for you. See
Platinotypes had a characteristic staining (transfer image) when kept
in a folder, wrapper or paper sleeve. The image was stable with no
fading. The paper mount, however, was often very acidic and
Since we are all guessing about possible causes of a brownish stain in an
old platinum image, I thought I'd mention this as a possibility.
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