Pd Test Strips
A set of strips showing how Platinum responds on different papers. I've found it hard to get Arches Platine lately, so I did a little test to see which papers worked well with palladium. I bought a variety of papers at Artist & Craftsman in Berkeley. Those papers that were marginal I also tried giving a short soak in 3% oxalic acid; this generally made them much more responsive.
Some of them hadn't cleared completely by the time I dried and scanned them. This test was about the blacks, not their ability to clear.
Also tested: Arches 88 and Copperplate, which don't work at all (too absorbent), and Stonehenge White, which works reasonably well, though benefits some from acidification as well.
Down below I also extol the virtues of Weston Parchment and St. Armand Canal.