100% Polyester fabric coated with polyurethane which makes it soft & gentle on the skin & comfortable on the body. One of the main features of it is to remain soft & comfortable when in use. It even gets softer under body heat, moulding to the user's shape & that of the mattress meaning extra comfort for the user. This coating is protected against fungi & bacteria. This product is water proof & flame retardant according to BS7175.