Pellon 725 Heavy-Duty Wonder-Under 17″ x 10 yards Bolt. Color: White. Fiber Content: 100% Polyester. Application Method: Fusible. 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 fabrics care requirements.