The Emma Mattress Cover top is made of 99% polyester and 1% elastane. The bottom cover is made of 87% polyester and 13% polypropylene.  It helps regulate the humidity and release moisture giving you the ideal sleeping climate. The side cover is made of 100% polyester which supports air circulation and provides grip to the underside of the mattress, preventing it from slipping on the bed base.   Please visit our website for further details: