I use to make plastic molds out of playdo. The playdo that the kids play with. I would spread the playdo with a doe roller, to about 3/8 of an inch. I would imbed the plastic body fully flush to level with the top. That would make a full body. I use to make those 1" grubs, 3" red worms for flyrod. All with no trouble at all. After I was finish with it, I would roll it up back in the container til next time. This is a Question. When and if you would make a real good impression of whatever you make, could it be baked in the oven and hardened. Never did it before,just an idea.