GB/T 23144 - 2023 provides the general principles of the two-point method, the three-point method and the four-point method for the determination of the bending stiffness of paper and Cardboard. The standard describes the basic principles of various methods, covering the requirements of test equipment, sample preparation specifications, loading methods and data measurement points, and also explains the calculation and presentation of results. Bending stiffness is related to the processing and use performance of paper and Cardboard. This standard provides a unified theoretical basis and operational guidance for paper companies, paper testing institutions, etc., to help accurately evaluate product mass, promote the standardization of testing in the paper and Cardboard industry, and improve product applicability.