Jakobb, to my knowing, Yupo isn't suitable for pt/pd or any other iron process w/o priming it with something - that will hold the emulsion - beforehand. (Said that, I don't know anyone doing pt/pd on Yupo BTW...) You can directly print on Yupo with tempera or casein processes, both colloid-dichromate processes which have quite strong and sticky binders... The problem you experienced isn't chemical (the paper is inert to the chemistry of pt/pd) at all, it's a 100% physical problem - the paper just didn't hold the emulsion / image.
Last edited by Loris Medici; 03-03-2013 at 05:15 AM. Click to view previous post history.
Reason: fixed few typos + a small addition