I can attest that even after over 3 months of use, these products are still in perfect condition. The pans have been used many times, (I've really been on a cookie roll lately - peanut butter cookies & snickerdoodles mostly...mmmm!) and they're absolutely unmarked and look brand new.  I have no complaints about this product, my cookies come out perfect every time.  They don't stick, and the pans are very easy to clean.