This part of ISO 12625 specifies a test method for the determination of tensile strength of perforated lines of tissue paper and tissue products. It uses a tensile-testing apparatus operating with a constant rate of elongation. The calculation of perforation efficiency is also specified in this document. It is expressly stated that the detection of impurities and contraries in tissue paper and tissue products should be applied according to ISO 15755. For the determination of moisture content in tissue paper and tissue products, ISO 287 should be applied.