If you're into playing around with materials... check out this blog.<p><a href="http://open3dp.me.washington.edu/?cat=6" rel="nofollow">http://open3dp.me.washington.edu/?cat=6</a><p>This dude is on the cutting edge of new material stuff. A lot of it is for Z Corp stuff, not FDM, but you might find some interesting nuggets there.