Hi folks, I have a few Styrofoam heads that I'd like to turn into creepy props, but I'm clueless as to what material to use if I wanted to build up the shape without carving the foam. For example, if I wanted to create a larger nose or more dimension for the cheekbones, and I wanted it to be durable and fairly solid, what do I use? Great Stuff? Plaster? I read somewhere that plaster of paris gets "hot" when mixed with water?! Really? ...And I'd rather not use paper mache strips. I guess I'm looking for something thick, but easy to work with. What would you suggest? Thank you in advance for all your input!