The Guru is stumped.
I cranked my iron up to the highest setting. I ironed with the fabric on top. I ironed with the fabric on bottom. I ironed with the fabric sandwiched between two pieces of waxed paper. I seriously considered ironing while facing west while standing on only one leg while the dog sang to the cat. (The cat wouldn't cooperate, the stubborn, stuck-up cuss.)
The parts of the paper that got hit with the heat do feel ever so slightly less waxy than the rest, but I can't see or feel any trace of wax on the fabric. It didn't even make my iron plate shiny.
I used Cut-Rite. I wonder what ButtercreamCakeArtist used ...
enquiring minds want to know ...