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