When I was in college we made plaster hands by covering our hands with
melted wax (be very careful it isn't to hot, especially when you put the
first layers on. We did this by painting our hands with melted wax/parafin
until we had a very thick coating about 1/2" or more. When the wax cooled we
carefully started wiggling fingers little by little to free them from the
wax and then carefully pulled our fingers and hand out of the wax which
created the mold. (Easier said than done, but a lot of fun.) We then poured
plaster into the wax molds.
We then painted them, and since this was the sixties they were really wild.
It's important to think about the position of your fingers in
I don't know if this would still be appropriate or do-able in a classroom
situation, but it was sure fun.