From: Liam Lawless (liam.lawless@blueyonder.co.uk)
Date: 12/02/02-10:05:50 PM Z
Richard,
Yes, I'd say so, except to note that even a tiny bit of silver in the
highlights - too little to register as image density - may cause some
discoloration on toning. You therefore want to make your test prints from
negs with very dense highlights - a Stouffer would be ideal, or mask part of
the image with, e.g., a coin. Polysulphide tones without prior bleaching,
doesn't it? If the toner has no effect on the "darks" of the image, then
it's a fair bet that hypo has it changed to suphide, but I'd guess that the
silver particles in VDB/kalli are so fine that the toner will bleach them to
a large extent... perhaps even if they're largely sulphide already. (I used
to find that I could bleach sepia toned images on warm tone papers with
iodine, whereas it wouldn't touch sepia on bromide papers.)
Another point to note is that if your prints are on buffered paper, they
will probably have formed a small amount of (insoluble) silver carbonate in
contact with the sensitiser (which I think - but am not absolutely
positive - contains an excess of silver nitrate). If so, this might confuse
the results.
Yet another possible complication comes from the chlorides usually present
in tap water, responsible for the milkiness seen in the first wash. If the
first rinse is under the tap, insoluble silver chloride will form with the
unused sensitiser, and chances are that a little will be retained in the
paper. Rinse for half a minute in each of two changes of pure water to
avoid this. Afterwards, continue washing under the tap if you feel more
washing is necessary.
But the bottom line is does the image stain in toner when it hasn't been
fixed? If it does, the exact reason isn't too important - we know we have
to fix. Probably best to do your tests on buffered paper since most papers
are buffered now, and we may not always know if what we're using is or not.
Do let us know what happens...
Liam
-----Original Message-----
From: rurmonas@senet.com.au [mailto:rurmonas@senet.com.au]
Sent: 03 December 2002 13:21
To: alt-photo-process-l@sask.usask.ca
Subject: RE: toning VDB & kalli - 2 questions
Quoting Liam Lawless <liam.lawless@blueyonder.co.uk>:
> To test whether any sensitive stuff is present, put a spot of
> sepia toner solution in a highlight area. Don't think I've ever tried it,
> but I'd bet a millionth of a dollar that the fix is needed.
I can't remember where I had come across the silver sulphide theory, but
have not had any luck finding a chemical proof one way or the other. So I
guess I had better do some tests.
What I propose is to make 3 VDB prints, with exposure as equal as I can.
Then:
Take one of the prints in an unfixed, but washed condition and put it in a
polysulphide toner. This should stain in the highlights / borders if any
unwanted silver compounds remain on the paper.
Take a second print after fixing + washing and put it in polysulphide toner.
This will tone further if there is any unconverted silver around.
The third print will be fixed and washed and is the reference print for
comparison to 1 or 2.
Do these tests seem resonable?
Richard
--- Richard Urmonas rurmonas@senet.com.au ------------------------------------------------- This mail sent through SE Net Webmail http://webmail.senet.com.au
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