ok, so I have one and a half sides done. Its turning out nicely. I don't know bout my stump anymore, my IDEA is shot on that, at least, for now!!! I WAS going to make it out of great stuff, may still, but its been changed... I found that greatstuff falls when wet, if you layer too much on, if your impatient. As I am.
so, the background is made out of... orchid potting bark and gorilla glue (which is a type of great stuff-100% waterproof, 100% nontoxic when cured) it DOES foam up like great stuff, but not to the extent, and it comes out as a liquid. I learned that to apply it, I needed to spread it out first, then put a HUGE THICK layer of the orchid bark over it, so that when it expands it holds the rest of the bark, without leaving... well, white foam.
you can see the foam sticking out on one side, and its not called gorilla glue for no reason!!!
So I'll be layering another layer over that: one bag will cover three sides, the bottom, and anything else I want it to
PS: use gloves. Great stuff is something a girl could use to wax her legs for SURE