I recently made a potato bag in a sewing class. They assured me that by using 100% cotton batting, that it would not catch fire in the microwave, "It's the cheap batting that has metal in it that catches fire". Well, not so! not only did it catch on fire, it ruined my new microwave! I made several for others as gifts and I had to call, email,or Facebook them all warning them to not use them. I was wondering how many of you have had Potato bag fires?