This part of ISO 12625 specifies a test method for the determination of thickness and bulking thickness@ and the calculation of apparent bulk density@ of tissue paper and tissue products under a pressure of 2@0 kPa. NOTE This part of ISO 12625 has been developed to provide a consistent test method for the determination of thickness and density of tissue paper and tissue products. Corresponding test methods for paper and board in general are covered in ISO 534. 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.