A tear resistant film comprises more than five layers situated one on the other in a parallel array. The layers are individually selected from a stiff polyester or copolyester, a ductile polymeric material, and optionally, an intermediate material. The stiff polyester or copolyester is oriented in at...http://www.google.co.uk/patents/US5427842?utm_source=gb-gplus-sharePatent US5427842 - Tear resistant multilayer films and articles incorporating such films
