I would suggest going down to the local building supply and pick up a 4'x8'
piece of Styrofoam wall insulation. They run about $10 to $12 and you can
cut approx 400 4"square pieces of foam to be used for bases for sculptures.
I'm also going to try to use them as printing plates as well (I got the
dense blue board, not the white Styrofoam board covered with foil)