RE: Pt./Pd. question acid pre-soak

True, that is my question. As Sandy explained he was interested in
combination of acid with developer.

I don't believe that it is just an acid/pH issue in terms of what is going
on. That's just my take on the use of oxalic acid and pre soak. I threw out
my best guess at to what is happening and I'd hoped that it may provide
Sandy with other insights.

I tend not to use papers that require me to do pre treatment of it before I
can use it. I also think all of those related issues are important to the
whole picture.

Kerik said that it had effects with more alkaline papers, this is why I
pointed out paper as an issue.

Eric Neilsen Photography
4101 Commerce Street, Suite 9
Dallas, TX 75226
214-827-8301
http://ericneilsenphotography.com

> -----Original Message-----
> From: Ryuji Suzuki [mailto:rs@silvergrain.org]
> Sent: Tuesday, August 09, 2005 11:02 AM
> To: alt-photo-process-l@sask.usask.ca
> Subject: Re: Pt./Pd. question acid pre-soak
>
> From: Eric Neilsen <e.neilsen@worldnet.att.net>
> Subject: RE: Pt./Pd. question acid pre-soak
> Date: Tue, 09 Aug 2005 00:24:16 -0500
>
> > It is really a question of," Why does oxalic acid promote a higher
> > Dmax for PT/PD prints?" In what conditions? For both FO and AFO, RH
> > factor, Paper type?
>
> That's your question and not Sandy's or my question. Sandy's question
> was whether the pH change was the sufficient condition to improve the
> print, or something other than pH change given by oxalic acid is
> necessary. To test this, I suggested to avoid organic di- or
> polycarboxylic acids for comparison because the results are
> uninterpretable.
Received on Tue Aug 9 12:08:14 2005