I made a couple of potholders/microwave bowls with 3 layers of cotton batting ..... it took extra time sewing more slowly but I like them .... absolutely. They were nice and thick and after washing, they were "bunchy" but no heat penetrates through them. I don't think I'll make too many but for my own use, they are perfect. I'm thinking about making another one (micowave bowl jacket) with a layer of flannel between the 2 layers of batting to see how it works. I look forward to see how your potholder turns out.