I was cleaning out some containers of fabric the other night, and I used this method to decide if they were cotton or cotton polyester blends. The ones with polyester melted and had a rough edge where it had burned, the cotton was just black and crumbled to ash...course I spent the next several hours obsessing about whether or not what I had done was dumb and that the fabrics I kept would suddenly spring back into flame! :roll: :? I knew I had extinguished them completely, but I am a worrier :shock: