The GB/T 457-2008 standard describes methods for determining the folding endurance of paper and Cardboard, including the Schopper method and the MIT method. The Schopper method is suitable for paper with a thickness of less than 0.25 mm and a tensile strength greater than 1.33 kN/m, and for Cardboard with a thickness between 0.25 mm and 1.4 mm; the MIT method is suitable for paper and Cardboard with a thickness of not more than 1.25 mm. The standard helps to evaluate the durability of paper or Cardboard in practical use by measuring its folding endurance under standard conditions.