Type of Foam

[shtick]

I got a huge 1" sheet of some very dense grey foam. It was used as padding in a box. Does anyone know what kind of foam this is? Would it be suitable for making puppets?

 

[Buck-Beaver]

Does it absorb water easily? If not it's probably some kind of closed-cell foam. I use that a lot for puppet bodies, but usually I use 1/2 inch thick sheets.