I ordered the Microwave Potato Baking bag supplies from Keepsake Quilting. I made the micorwave baking potato bags for Christmas gifts. The potato fabric was so cute. I used the correct batting and cotton thread. The bags all burned up in the microwaves. I was so embrassed. I contacted the company and they said there had been no other problems. I got the sewing machine, that I used for the project, out today. I think it may have had a prewound bobbin on it... do you think that could have caused my bags to burn?? I could not find anything on the package of prewound bobbins to indicate what kind of thread is on them. I really like those bobbins. What do think of using them for quilting? I use them for embroidery.