Thank you for your information ladies.
Cari I don't know what machines you have but my Babylock was having a hard time going through the 8 layers so I called my dealer [he is cussing these fabric bowls]. He has had so many inquires, I don't think the newer machines have the umpha that the older mechanical machines do, my personal opinion.
I used quilting cotton and a Warm and Plush, which is 100% cotton and microwave safe, however it does feel and look thicker than the Wrap and Zap or other 100% cotton microwave safe products. I might save that for just one layer of batting for table runners.