> Another thought. You have to be very carefull not yo overfix a Van Dyke
> print. Overfixing will bleach the print and, of course, reduce the
contrast. > > Bob Schramm >
Fix in 25 g of sodium thiosulfate per 500 cc of water with *continuous*
agitation for no more than 2 timed minutes.
My tests show, BTW, that after one minute, bleaching begins on a thin
paper, but this gives you a one-minute margin of safety. If you're using
thick paper, do your own tests. Note, however, that in every test I made,
the 3 to 5 minutes given in the books was TOO MUCH.
Also, I *strongly* advise against giving only a 20-second first rinse as
someone has suggested. As I understand VDB, this would risk leaving
residual iron, which would degrade your print sooner or later (probably
sooner). Also, I see no reason why that could possibly improve contrast --
assuming the rest of your process is OK & you're not just washing off your
image.
If your existing negatives are too thin, try intensifying them. I think
greatest intensification with currently available materials would be
chromium intensifier (mixed from your own potassium or ammonium
dichromate), washed and dried & followed by selenium toner, one part
Kodak Rapid Selenium to 2 parts hypoclear or water.
As for mercury intensifiers (note that I put all this in one post so those
who pay per post can save money, OK?), as I recall, Victor's Intensifier
was a formula, and I think Gibson's "Darkroom" (Lustrum Press) has it in
article by, what was his name, Dick someone? -- did the grainy birds in
store window.
I have in my darkroom drawer a roll somewhat smaller than a roll of
lifesavers, labeled "Jodquecksilver Verstarker", which is a mercury
intensifier. I bought the last two rolls they had at Olden Camera (when
they still had a darkroom department), used one roll, which, as I recall
didn't intensifier any better than Chromium Intensifier. The working
solution still sits in jar on the shelf, and my conscience never let me
use this roll. Not that I never do an eco-bad act, but somehow the
****mercury**** seemed too wicked.
However, for those who want that fun brown tone without toning a silver
print in mercury, here's one:
Bleach a b&w print with a bichromate and hydrochloric acid bleach (lab
manuals should have a few formulas). Wash, dry. Expose in sunlight. Image
will print out a nice brown color, depending on paper. As I understand it,
you now have a silver chloride print -- or a semi. It may take a few days
or a week. I did this through the window. No need to leave the print in
the camelia bush.
Judy