i see an exhibition at the "maison européenne de la photographie" called
platinum test .In fact there lot of test made by penn irving when he begin
to make platinum prints (we can see the paper he use and things like that).
as intrduction to the exhibition they told that he used platinum, palladium
and iridium.
making platinum palladium print, i never try to put iridium salt in it and
would be interesting by someone who can tell the effect it had on the
picture.
thanks to all
nze christian (france)