Re: iron-silver processes

>>> rs@silvergrain.org 12/12/05 2:06 AM >>>
>>Thanks for the link to the results of your experiment. This is
interesting. I gathered that #7 and #9 are toned versions of #2. Is
this correct? <<

1, 2, & 3 are untoned. #1 is single-coated and the rest are
double-coated. #3 is on a different paper than the rest. The remainder
are all toned versions of #2. Otherwise, same emulsion, exposure,
toning time, and wet time.

>>What do you get if you dilute Poly Toner 1:200? What about 1:1000?
(both after fix) What do you get if you tone for shorter time?<<

Dunno. I did the test only in response to some statements about being
able to tone VDBs in certain toners and included the quick Polytoner
tests because someone suggested sulfide toning might be possible. The
comparison is really meant to be just a quick FYI. I like the color
result from the Clerc's gold-toner formula (#11) and am content to stick
with that. The colors of the Polytoned and selenium-toned versions are
less appealing to me than the untoned prints so I doubt I'll ever use
those toners. So far I have not witnessed any fading with the untoned
or gold-toned prints with my processing so I suspect reports of
longevity issues with older, historical kallitype/VDB prints have to do
with poor washing, clearing, or paper.

>>On my screen, #9 doesn't look too bad, maybe except for the raised
fog. Perhaps you should test whether #9 is significantly resistant to
oxidative attacks, together with #2 and #10, using peroxide fuming
test.<<

Not sure I'm seeing the fog you speak of. Can you describe the peroxide
fuming test?

>>In relation to the raised fog level with toning, I suspect something
reactive is in the paper. Iron and silver are two obvious
suspects. Did anyone test for the presence of these? (even crude ones
would suffice)<<

I didn't test for them, but I assume silver is the culprit since the fog
level decreased substantially when the toner was applied after fixing.

>>Do you use citric acid and fix baths one-shot? Do you mix sensitizing
solution and citric acid bath with tap water?<<

I use the fixer one-shot. The citric bath is mixed to a 500ml bath and
discarded after the printing session. Both are mixed with tap water.
For these tests, both solutions were freshly mixed.

>>I know citric acid is a popular clearing agent but do people use
superior iron chelators such as saturating solution of Na2EDTA? (Of
course, there are a lot of other things that may be worth testing.)<<

I'm sure someone does, but I haven't.

Joe
Received on Tue Dec 13 07:47:08 2005