katherine
can the brown stain be removed with a clearing bath?
--- Katharine Thayer <kthayer@pacifier.com> wrote:
> 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 Tue Sep 28 09:35:19 2004
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