Metalized mylar is layered between polyester fleece to create a high-quality barrier that reflects heat or cold. This special combination of materials is very flexible and easy to sew through. Once you have sewn it into your project, you can machine wash and tumble dry with no bunching! A handy 3/4-yard cut is enough for a large lunch bag or several potholders. Insul-Fleece™ is heat-resistant only - it is not heat-proof or fire-resistant. Use of an extra layer of cotton batting is recommended for pot holders. Use caution when handling hot surfaces with any insulated fabric craft project. 27" x 45" Insul-Fleece, a metalized mylar insulated interfacing. Made in the U.S.A.