U of S | Mailing List Archive | alt-photo-process-l | Re: Potentially stupid pt/pd question

Re: Potentially stupid pt/pd question

>Check that your developer has some excess of oxalic acid. I usually have
>undissolved oxalic acid at the bottom of my bottle. Perhaps chcking pH
>would be the
>best way of doing it. I have had my developer for years now. It gets
>after every printing session. Never found a reason to go to one shot >

Marek, thanks for the tip; I'll try that.

I too have been using the same jug of developer for quite a while now. 
However, it's been a while since I've replenished it...that wouldn't cause
it to stain the paper, would it?

> Rinsing the print may be your problem. If your water is above pH
> neutral (>7.0), the rinse itself can lock the ferric oxalate into the
> paper fibers. I would put the print straight into the first clearing
> bath, which should ideally be something acidic - say 1-2% citric acid
> or HCl. Stain is caused by the unused ferric not being removed, not
> by the developer. In fact, one trick is to let it soak in the
> developer for 5 minutes or so before you move it to the first
> clearing bath. Your developer will eventually load up with ferric,
> but it is effective as long as the pH of the developer is around 6.0
> or so.

Clay, I definitely tell you it's not the ferric that's staining, although
it is the same color (which is why I initially thought it was a clearing

The entire sheet of paper is stained (front and back), not just where it
was coated.  The "paper white"

It looks almost as if it spent some time soaking in a tray of coffee.

Camden Hardy