From Pellon website: Pellon® SF101 Shape-Flex® is an all purpose, woven, fusible interfacing. It provides crisp support for collars, cuffs, yokes, pockets, facings, and other detail areas of a garment. It can also add body and permanent stability when used as a backing for needlework and punch embroidery. Shape-Flex® is intended for light to medium woven and knit fabrics, including oxford cloth, chambray, gingham, madras, tattersall, pincord, flannel, and polyester/cotton blends. To pre-shrink, fill a sink with warm water. Place interfacing in water for about ten minutes. Do not put in washer or dryer by itself or you may loosen the adhesive. Gentle squeeze out excess water and allow to dry.