Pellon's Wrap-N-Zap is a microwave safe product is made of 100% Natural Cotton Batting. When used in the microwave, it will trap the moisture inside to produce a perfect baked potato or a well steamed ear of corn. It can even be used for warming rolls and tortillas. DO NOT USE THIS PRODUCT IN THE MICROWAVE WITHOUT FOOD. Washable by hand or machine. Dry cleanable. Please note: do not wash batting until covered in fabric / completed project. Product has no expiration date.