This part of ISO 12625 specifies a test method for the determination of thickness and bulking thickness and the calculation of apparent bulk density and bulk of tissue papers 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.