Re: Potassium Oxalate developer for Platinum printing

As to Core Breukel stating "Jeffrey Mathias advices to use the developer
single shot, reusing will cause fog."

This is an absolute and does work. However, in practice the important
thing is to replenish periodically, keep acidic, and replace when a
little fogging becomes noticed. It is definitely not good to keep any
used PO for longer than a couple years even if kept dark and cool (test
and find out.)

One must keep in mind that anything that goes into the PO may stay there
and end up on, in or affecting a subsequent print. The largest concern
of mine is actually contamination by contrast agents.

Someone mentioned exposure to UV light of the solution. I believe this
may not be good as the fine metal which results may cling to the paper
fibers and not clear as readily as the unexposed metal salts, resulting
in fog. I suspect that the fog from old PO is from subsequent metal from
the washed off unexposed coating. A good amount of the unused coating is
cleared in the PO, even with short times.

-- 
Jeffrey D. Mathias
http://home.att.net/~jeffrey.d.mathias/