I have used the self hardening clay the last two years. It definately
leaves something to be desired. Small parts tend to fall off.
I don't know if you can use slip on it or not. I am a bit nervous to get
it wet, so I'd love some opinions too.
Also, how did your students get their plaster masks and hands to look like
they are coming out of plastic wrap or cloth? Can you explain this
process? I love it!