The ISO 1 2625-6: 2016 standard specifies methods for measuring the gram weight of tissue paper and toilet paper products. The standard provides detailed test procedures to ensure the conformity and accuracy of paper in production and quality control. The gram weight, in grams per square meter (g/m ²), is an important parameter for evaluating paper mass. The requirements for measurement equipment, sample preparation and test steps are included in the standard to ensure the Reliability of measurement results. Compared to the previous edition, the second edition updates the accuracy data and formulas to improve the accuracy and conformity of measurement. This standard provides a uniform test specification for paper and paper product manufacturers, testing institutions and related fields.