Pot holders, oven mitts, and casserole covers are made functional and safe with InsulBright Consists of hollow, polyester fibers needlepunched through a nonwoven substrate and through a reflective metalized poly film. The hollow fibers resist conduction while the reflective metalized poly film resists radiant energy resulting in the energy, hot or cold, being reflected back to its source. No Prewash Necessary. Machine Wash and Dry. At least one layer of cotton batting is recommended with InsulBright when used in oven mitts or pot holders. InsulBright is heat resistant, NOT heatproof.