The Hippychick Tencel fitted sheets are high quality, discreet, breathable and 100% waterproof. It is difficult to believe that something that feels so soft and luxurious can be so practical. Tencel is a naturally hygenic fibre made from 100% biodegradable wood pulp cellulose. The wood used comes from tree farms practising sustainability and is guaranteed by the European Programme for the Endorsement of Forest Certification (PEFC) quality seal and the international Forest Stewardship Council (FSC) standards label. It is cool as linen, soft as silk and even more absorbent than cotton. Tencel\'s unique moisture absorption capacity draws away moisture and helps you keep cool even on the hottest nights. Without moisture the growth of bacteria is inhibited. Without bacteria, mould and mites similarly find life more difficult. All this is achieved without the use of added chemicals that otherwise might be harmful to sensitive skin. The polyurethane layer also acts as an anti-allergy barrier protecting against dust mites, a major cause of hayfever and asthma. The undetectable polyurethane layer makes these protectors 100% waterproof without the awful feeling of lying on a crisp packet!