I used Funky Foam with no issues, but the Hobby Lobby available carried only the 8 x 12 size, my slab mold is 12 1/2 inches long. So I checked out the local Joannes and no Funky Foam, but they did carry Foamies in a 3 foot by 6 foot sheet, and I'm thinking should be ok. Wrong. First pic is what foamies did to my soap. Second and third is after the clean up. It's a goat's milk layered soap, no color on the bottom, TKB's green on the top, along with some ash. Fragranced with cool cucumber. My first attempt at layers and goat milk - I used powdered. PS Guess what color the foam was