Katharine Thayer wrote: (Sept 20)
>
> Loris Medici wrote:
> >
> Actually I liked the combination of cyanotype
> > with the warm background (which is tanned gum - probably plus the dichromate
> > stain too)
>
> Yes, if there is dichromate stain in the hardened gum it will impart a
> warm tan or brownish color, unless it is so heavily overexposed that it
> actually turns green, but hardened gum by itself is colorless.
Retraction:
Well, I thought I'd seen green dichromate stain once or twice after
egregious accidental overexposure, but after trying unsuccessfully to
produce green stain in unpigmented gum, I am forced to consider that my
earlier perceptions of green may have been influenced by the color of
the pigment. At any rate, in my experiments with unpigmented gum, even
after six or eight hours in direct sun the only color I've seen is
brown. Once it gets to a certain brown, which doesn't take more than
five minutes or so in the sun, the color stays the same brown shade no
matter how much excess exposure is applied.
Katharine Thayer
Received on Mon Sep 27 21:51:31 2004
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