The standard specifies methods for determining the thickness, expansion thickness, apparent bulk density and volume of toilet paper and tissue products. The standard specifies measurements at a pressure of 2.0 kPa to ensure conformity. It covers the testing of single-layer thickness, single-sheet thickness and expansion thickness, and their corresponding apparent bulk density calculations. Through the standardized Measuring method, the standard provides an accurate technical basis for the quality control of tissue paper products. The new version of the standard adapts the accuracy data and specimen prepative methods to suit the capabilities of existing equipment and calibrating procedures.