An affordable light-blocking material, SunBloc Series SB9100 reduces solar heat gain both winter and summer. SunBloc Series SB9100 room-darkening window shade fabrics are constructed of close-woven fiberglass sandwiched between two layers of tough, flexible vinyl. Available in ten decorator colors on the inside and white on the outside. Flame, fade, and mildew resistant, washable and tear proof. Designed for the toughest service, without that “institutional” look.