Judy Seigel (jseigel@panix.com)
Sat, 20 Mar 1999 15:53:50 -0500 (EST)
On Sat, 20 Mar 1999, Kevin O'Brien wrote:
> Mine was the simple coating formulation:
> Ferric amonmium citrate 90g
> Tartaric acid 15g
> Silver nitrate 25g
> Distilled water to 1200ml
Jacques, are you "developing" this formula in a "developer" other than
water? Because that's the formula we know as Vandyke brown, which we
"develop" in plain water, and then fix and wash.
What we have called "kallitype" and what is in various manuals,
dissertations and articles (especially the photo magazines of the early
1900s) by that name is similar to the platinum formula (fe something else
(chloride?), & so forth) and is developed in chemicals, the most popular
having been Rochelle Salts, or a variation thereof, which I found the
worst -- shortest scale, grainiest highlights.
I daresay it changes with different formulas, papers and developers, but
in my experience the best developer was sodium acetate with tartaric acid.
We had this on the list 2 or 3 years ago.
Also, folks are talking about coating "sinking in." I rarely bet less
than a million dollars, but ..... in my experience, except for pl-pd
which just LOVES to sink in, there's rarely a sinking in problem in any
medium if you're not heat drying. Then it probably isn't actual "sinking
in," is it?, but the tones do get blown out.
Most standard papers that are not "waterleaf," that is, that have a size
in the making, do not need extra size. In my experience, vandyke brown
was *worse* with every size I tried unless it WAS heat dried.
When I used to heat dry (hairdryer) , before I figured that out, it
usually needed an added size, and even then tended to plate out, which may
be what you're talking about with "solarize"?
That varies by the way, sometimes you see it wet & not dry, sometimes dry
& not wet, and sometimes it appears in time, pretty at first and then
blotches. I used to love it til I saw it was a time bomb. Sorry about
that.
Judy
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