Re: Cyanotype colour

Judy Seigel (jseigel@panix.com)
Wed, 17 Apr 1996 09:38:19 -0400 (EDT)

On Wed, 17 Apr 1996, Russell Young wrote:
> In over 20 years of fooling with them, the only simple & stable
> method has been *selenium toning* with Kodak Selenium Toner.
> Make a fairly dilute bath, submerge the cyanotype, agitate gently,
> watch the colour shift. Be careful because if you leave it in too
> long, it will bleach the image.

Upon reading this astonishing news I quicckly cut a cyanotype 21-step in
half the long way, gently immersed it in selenium 1 to 20, raptly watched
the color turn purply blue, carefully rinsed after 30 seconds, intently
noted the color getting paler in plain water, yet hopefully set it to dry.

This morning I eagerly examined the halves rejoined & clearly saw:

What had begun as bright greenish blue in the original cyanotype, then
become purply blue after "toning," was now nearly reverted to the initial
color, only grayer. The top two steps, #11 &12, had disappeared
entirely; steps 7 thru 10 wwere considerably lighter and steps 1 thru 3
slightly lighter.

Moreover, either a plain ammonia or weak HCL bath will have the
same effect -- a temporary excursion into a beautiful purple that fades
on drying. ("Selenium" toning is unlikely absent silver, I suspect. Anyone?)

The "literature" cites various "purple" cyanotype toners, but observant
authors usually note that none is stable past the 3rd day.

Furthermore:

1. Considerable variation in cyanotype color occurs by paper alone. Test
samples.

2. This was thorougly discussed last fall (about October). I gave detailed
instructions for a good cyanotype brown. Bob Schramm posted an "improved"
cyanotype formula and lead toning to a soft, purplish blue.

3. Whoever is interested in such issues but fails to read the archive is
missing much of what they came for.

4. I said that already.

Judy