o to cover my cake and decorate it because I had to keep putting the stuff in the freezer and it tore and bubbled all over the place. It was ridiculous like working with melting taffy. I live in Washington state and it was October so humidity was definitely not the problem. My last batch of white was workable but also stickier than usual so pieces kept sticking to the mat (even with cornstarch or shortening). So far both batches of black that I purchased were great and didn't have these issues. 