Can someone answer a question?

I have a mask that has a thin spot in the latex. Is there anything permanent I can place on the inside of the mask to make the thin spot hold shape better?

Yes you can dip a piece of pantyhose in liquid latex and make a patch for it, on the inside obviously

Build up layers of latex inside.

ToddB

yep

If you want it really stron I use latex and cheescloth, You seperate it into 2 layers
Brush latex on the spot, then lay the cheeseclot on the latex and smooth it.
Add another layer of latex or two then repeat, its like the cloth in fiberglass