Well, maybe not quite everything, but Angela's (aka CraftyGoat's) most recent blog entry does bring up some interesting points. She shares her notes from a Q&A session Polyform offered at the IPCA retreat, so this is very fresh information. I highly recommend giving it a look, if you haven't already-- especially if you regularly use any of the Polyform clays (SculpeyIII, Premo, Studio by Sculpey, etc.).
I was surprised to read that Premo no longer contains phthalates. I'd heard that Kato Clay had made the switch, but nothing about (most of) Polyform's lines of clay. I'm not sure how I feel about that. If the phthalates really were a significant health risk, then of course it's good to avoid them, but I always wonder how much things of this nature may be blown out of proportion. I also wonder how much of a reduction in shelf life we should expect, now that so many brands are going phthalate-free... (This makes buying in bulk and/or stocking up during clay sales seem a bit more risky. Better get busy using up some of my more recently stock-piled clay, huh? (g))
It was also interesting to read that the recommended temperature is a little bit lower than what you need for optimum strength. (Apparently the manufacturers prefer to err on the safe side. Can't really blame them there, but it's good to have the facts.) I guess people knew what they were talking about, all these years, when they've said you're ok if you don't go over 300 degrees. I know I often find my oven's temperature tends to creep up higher than 275, but I've only scorched something once, and that was because it was too close to the heating element.
Anyway... Good stuff to know! Thanks for sharing the info, Angela!