Thanks for all the responses,Problem was this was not a new bag, have used it lots of times and the microwave is not new, Hope my microwave isn't causing the problem. To go along with this problem. if you are recharging batteries and it says do not leave unattended please pay attention. my son was recharging some batteries earlier this week and it caused a house fire. Caught early enough so mainly smoke and water damage. He was very lucky. Sharon in okc

I make adult bibs to sell and am curious to know how thick this 100% cotton batting is. Is it equivalent to warm & natural cotton batting sold for quilts or thicker. It is only available online where I live and I hesitate to by 40 yds. if I can't use it for this purpose. Thank-you for any feedback.