Probably you've got off-line replies to this question (many list members
messages bounce; probably because of the recently installed / configured
anti-spam software the server is running - Gord can you please
elaborate on this?).
Well, my guess (speculation) would be: (Please correct me if I'm wrong -
but not harshly...)
Oxalic acid is used to neutralize / eliminate the alkali buffer in the
paper. Since pt/pd coating solution is acidic, putting it onto an alkali
paper will neutralize some of it; impeding image formation (probably
giving grainy & flat prints and weak Dmax). Maybe some other mild acids
also can be used(?) but since oxalic acid is usually part of the
sensitizer (Ferric Oxalate), it makes sense to use it - instead of
adding an alien compound into the process. Kallitype sensitizer is the
same as pt/pd, so neutralizing / acidifying an-otherwise-non-suitable
paper with oxalic acid may also work for Kallitype.
(?)
Regards,
Loris.
-----Original Message-----
From: Michael Koch-Schulte [mailto:mkochsch@shaw.ca]
Sent: 27 Ocak 2006 Cuma 05:30
To: Alt-Photo-Process-L
Subject: Kallitype Paper Pre-Soak, Sizing
Recently, I read that someone pre-soaked their platinum/pd papers in
Oxalic Acid solution prior to coating. Could someone explain to me why
this was/is done? Would the same hold true for Kallitypes?
~m
Received on Tue Jan 31 09:23:11 2006
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