I made potholders for myself just using W&N batting - can't remember if I used 2 or 3 layers, but I think it was only 2. They work just fine, no heat coming through. The design I used winds up with several layers of fabric in addition to the batting, so that might be a factor. If you're really concerned, make one without Insulbrite and test it out. Chances are it will be just fine.