This part of ISO 6383 specifies a method of determining the tear resistance of plastic film or sheet less than 1 mm thick, in the form of Standard trouser-shaped test specimens, tested under defined conditions of pretreatment, temperature, humidity and Speed of testing. The method is applicable to film and sheeting of both flexible and rigid materials, provided that the material is not so rigid that brittle fracture occurs during the test, or so deformable, in an irreversible way, that the energy used in the deformation of the specimen legs is significant (i.e. is not negligible) with respect to the energy used in tearing. The method may not be suitable for determining the tear properties of cellular sheet and film.