Thanks for your suggestions. I have used model magic
before but I find for certain things it doesn't show
details as well. I have not tried Amaco air dry clay
so I will give it a shot.
We were making small African mask models and we used
different types of air dry clay and almost all of them
cracked in half. They were about 1/2 inch thick,
which may have been too thin? I've also just tried
using the clay to make animal figurines, with those
cracking as well.