Odd... I used to use Wax Paper too back when I was working with Polyester resin... I tried it late last year with some West Systems Epoxy Resin to make some flat sheet stock (basically sandwiching 3 layers of chopped strand) and when I returned 2 days later, the epoxy resin had thoroughly bonded to the waxed paper! I mean it ate through the waxed surface and was into the paper itself!
Since I have been using Poly bag material.. It does not stick to that..
Epoxy resin is a different animal for sure. It bites into a lot of stuff Polyester resin doesn't. I love it though.