RE: cyanotype help needed

Hi:

I did some experimenting toning cyanotypes a few years ago. One method is
to bleach with a mild alkali and then acidify to get the image back. The
color of the resulting image varies somewhat with the kind of acid used.
Tannic acid give it a blackish brown tone

I played around with different acids, citric, acetic etc, and noticed some
subtle differences in the color of the blue depending on what acid was
used.

It may also depend on what alkali is used. I just used one alkali - can't
remember which one.

Sooo. you may want to experiment with some less valuable paper and see if
you can come up with something you like.

Gord

On Thu, 24 Mar 2005, Joe Smigiel wrote:

> Loris,
>
> In my experience the alkali solution and wash bleaches the image beyond
> that which the acid will recover. This varies between images/papers but
> I've always been able to lighten the image doing this, sometimes too
> much.
>
> joe
>
> >>> loris_medici@mynet.com 03/24/05 8:47 AM >>>
> Joe, doesn't it gain its old density (or very close to it)? When you
> acidify I mean?
>
> > -----Original Message-----
> > From: Joe Smigiel [mailto:jsmigiel@kvcc.edu]
> > Sent: Thursday, March 24, 2005 3:44 PM
> > To: alt-photo-process-l@sask.usask.ca
> > Subject: Re: cyanotype help needed
> >
> > Jan,
> >
> > Any alkaline solution would probably reduce the density of
> > the cyanotype and also lower the contrast. I've used weak
> > ammonia solutions, borax, and even dilute film and paper
> > developers to bleach back cyanotypes.
> > They will turn a lovely lavender color as they bleach. Go
> > slow using weak solutions in order to gauge the bleaching
> > effect with some precision. I would try a test on a similar
> > piece of printed paper in order to determine the proper
> > strength solution to use. After rewashing the print I always
> > acidify it again using weak acetic or citric acid and this
> > returns it to a blue color.
>
>

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Gordon J. Holtslander Dept. of Biology
holtsg@duke.usask.ca 112 Science Place
http://duke.usask.ca/~holtsg University of Saskatchewan
Tel (306) 966-4433 Saskatoon, Saskatchewan
Fax (306) 966-4461 Canada S7N 5E2
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Received on Thu Mar 24 23:33:02 2005