Re: Oxalic Acid for Pt./Pd.

From: Kerik ^lt;kerik@kerik.com>
Date: 09/15/04-10:13:09 AM Z
Message-id: <opsedlz7su9xluie@mail.kerik.com>

Sandy,

I routinely add some oxalic acid to my ferric oxalate when I mix it.
However, I don't think there is enough volume of sensitizer to neutralize
some of the more highly buffered papers like Fabriano Artistico Extra
White. The pH of ferric oxalate is about 1.5 even without the addition of
the OA. I think the presoak is the better way to go since the paper is
completely saturated with the acid and there is plenty of volume in the
tray to neutralize the alkalinity of the paper.

Kerik

> I get higher Dmax by about 0.10 - 0.20 with most papers in Pt/Pd.
> printing by first soaking in a 1% solution of oxalic acid, then drying
> without rinsing.
>
> Soaking papers this way is not terribly inconvenient, but I am wondering
> if anyone has experimented with adding oxalic acid directly to the
> sensitizer before coating?
>
> Sandy King
Received on Wed Sep 15 10:13:45 2004

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