RE: Kallitype Paper Pre-Soak, Sizing

I have almost certainly commented on this before. If not, you are
correct in that the oxalic acid (or other acid pre-soaks) works with
kallitype almost exactly as they do with Pt./Pd.

Sandy

>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 09:49:39 2006