Polymer clay in piece production...

I've done some. I put an older page of mine up at [1] with some pictures of one of the more successful results, a small space marine type guy. I wound up using him in the prototype for a game a friend and I put together. The orginal you see there is made with Sculpey, which I then resin cast to produce piles of clones (each copy of the game needs 5). People really got into us having our own little plastic bits (mostly our friends, and we've played a bunch of times at local clubs and small conventions). I've been using alumilite for casting. It's pretty easy to use and gets great results---the pieces are very solid & durable, and the casting is not too delicate in terms of getting measurements right and things like that.

For me it takes a lot of time, and I'll never be great at it, but it's also really rewarding and a neat skill to have in making prototypes and things like that.

[1] http://gicl.cs.drexel.edu/people/tjkopena/games/space-marine/

I thought I'd add that the Alumilite I mentioned uses RTV rubber like SiskNY mentioned. Basically, that means the process doesn't involve high temperatures, pressure, or anything like that. It goes like this:

- Make the piece.
- Build a little box around it, to contain the rubber
- Mix the two rubber elements and pour it on.
- 4 hours to a day later (depending which rubber you use), you can pop the piece out
- Mix the two resin components (the plastic is essentially an epoxy)
- Pour it into the mold
- Wait a minute or so, and then you can pop out your new clone.

The stuff smells pretty funky, about as bad as spray paint, but not as bad as a gloss sealant or whatnot. The resin gets hot as it mixes but not so hot to burn if you get it on you. If you get some on you, it usually peels right off. It generally will not just peel off your clothes/table though!

A starters box of Alumilite runs about $35US. That gave me enough to make a couple small molds like that pictured and a few others (e.g. a sheet of chits). I still haven't used all the resin that came with it, and I've made a ton of little guys and stuff.