[alt-photo] Re: Question for Platinum/Palladium printers

[etienne garbaux]

Mark wrote:

>For all you Platinum/Palladium Printers, I am curious what your 
>current practice is for clearing platinum/palladium prints.
>I use primarily Palladium with the Na2 method for contrast or I use 
>straight palladium.
>
>For clearing I use 3 baths of Heico Permawash dilute 1 ounce per 
>quart.  5 Minutes in each bath, then every couple of prints I dump 
>the first bath and rotate with freshest bath last.

I would never trust any Pt/Pd clearing process that did not begin 
with a reasonably strong acid (my preference is hydrochloric acid at 
1% or so) followed by a 10 minute rinse, pH neutralizing (2-3 minutes 
in a weak sodium sulfite solution -- you can use diluted commercial 
silver-gelatin wash aids for this), and a good long wash.

Some folks use iron sequestering agents these days rather than acid, 
but to the extent that there are insoluble iron compounds deposited 
in the paper (and there always will be), you really need the acid 
bath to solubilize them.

AFAIK, Permawash is just a typical silver-gelatin wash aid -- an 
alkaline solution of sulfites and sulfates, perhaps with some silver 
and calcium sequestering agents.  If it contains any iron 
sequestering agents, it is only by accident -- it was not formulated 
for iron processes.

Best regards,

etienne