Re: Re: Platinum/Palladium Questions..

William Laven (William_Laven@designlink.com)
11 Dec 1995 20:13:39 GMT

"as far as using the jobo for Pt/Pd printing, the problem I forsee is that
of the PT/Pd coming off the print while in the developer (happens with
some paper/developer combinations). The rotary action of the processor
would embed the metal particles in the paper fibers degrading the whites
and clean borders. This is very difficult to remove, and the solution I
use when working with these materials is stagnant development (no
agitation) after which a stream of water on the areas that the particles
have adhered to will wash them off, because they haven't been driven into
the paper by agitation." (from an earlier post)

I feared the same, but it hasn't happened with me and my trusty Jobo. I've
worked with 3 different papers and probably 5 different developers and 3 or
4 different clearing agents and haven't seen this problem. Overall, the
business of Pt/Pd and/or iron salts moving around and landing elsewhere on
the print is exaggerated I think. A proper clear would remove those
particles, quite easily in fact if they simply resided on the surface of the
paper having migrated from somewhere else. I think its overstating what
likely happens in the Jobo to say that it drives particles into the paper.
When I first started to use the Jobo I had these and other fears and made
many side by side tests with trays and little agitation and the Jobo never
failed me. Working with Potassium Oxalate and Sodium Dichromate as a contrast
agent, the Jobo is a godsend. Changing from one developer to another is a
cinch. With trays I'd have to empty the tray after every development and
rinse it out which, klutz that I am, would surely involve some mess. Besides
I can't fit 20x24 trays in my darkroom sink, but the Jobo does fine with
them. One could easily build bigger tubes out of PVC and use them on a roller
agitator and get the same efect and ease of use. I actually have a roller
agitator in the dakroom which sits by my Jobo so I can process two prints at
a time if they require different developers.

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