Abstract: The use of a multilayer film to store or retrieve information, said information being correlated to the multilayer structure of the film, and said multilayer film comprising at least two different types of layer, wherein each type of layer exhibits a different optical property and wherein the multilayer film comprises a plurality of layers of each of at least two of the different types of layer; a method of storing information, a method of retrieving stored information and a method of protecting against counterfeiting or fraud, which method utilises said multilayer film.

Abstract: The use of multilayer film structure comprising at least two unfilled layers of polymeric material substantially devoid of opacifying agent and at least two filled layers of polymeric material wherein said filled layers comprise at least 5% by weight of opacifying agent for providing improved tear-resistance in an opaque polymeric film, particularly a polyester film.