Package of 1 piece of Wonder Under, 15" x 3 yds rolled. Heavy-Duty Wonder-Under is a paper-backed fusible web with twice the adhesive of original Wonder-Under® that turns any fabric into a fusible fabric. It fuses fabric to fabric or to another porous surface such as wood or cardboard. It is especially handy with denim, canvas, or other heavy fabrics. Use Heavy-Duty Wonder-Under when extra holding power is needed. The product has no grain and can be cut and applied in any direction. The finished item can be washed or dry-cleaned according to the fabric’s care requirements. Acid-Free 100% Polyester.