This standard specifies the mass requirements, inspection rules, marking, Encasement, transportation and storage requirements of offset plate printing paper, and details the corresponding test methods. It is suitable for the production, inspection and sales of printing paper used for offset plate printing books, covers, illustrations and pictures. The standard covers the measurement methods of many physical characteristics of paper size, quantification, thickness, smoothness, folding resistance, stretchability, water-absorption, opacity, etc., to ensure that the product meets the printing requirements and mass standards. The standard refers to a series of relevant test methods and inspection procedures, including paper Moisture content, Color, Blue light diffuse reflection factor, Encasement and marking regulations, and test requirements under standard atmospheric conditions, providing specific guidance and basis for the production and quality control of offset plate printing paper.