The GB/T 2679.3-1996 standard specifies methods for the determination of paper and Cardboard stiffness, which is equivalent to the international standard ISO 2493:1992. The standard applies to the determination of paper and Cardboard with a bending moment of 2mN · m to 1,000mN · m, but not for corrugated fibreboards. Test methods include determination at a bending angle of 15 ° or 7.5 ° using specific instruments (e.g. Tabernacle and L & W instruments). The standard retains the test methods in the old version and adds new requirements for Miscellaneous instruments. The instrument needs to be calibrated regularly, and the sample handling should be in accordance with the regulations. Test results should be reported in mN · m units with standard deviation and coefficient of variation.