This International Standard specifes three test methods for determining the bending stiffness of paper and paperboard. The test methods differ in the type of loading mode, thus giving rise to the two-point, three-point and four-point bending test methods.For paper and paperboard in a low thickness range, the two-point bending method and the three-point bending method are suitable.For corrugated fbreboard and board with a higher thickness, the four-point bending method is recommended.The measurement conditions are defned in such a way that the test piece is not subjected to any signifcant permanent deformation during the test, nor is the range of validity of the equations for calculating the bending stiffness exceeded.In these bending tests, the test pieces of paper and board are regarded as “beams” as defned by the science of the strength of materials, see Reference [1].