ISO 4628-3-2017 "Assessment of Paints and varnishes - Assessment of the number and magnitude of defects and the strength of uniform variation in Appearance, Part 3: Assessment of the degree of rusting" provides a standardized method for assessing the degree of coating rusting. The standard compares the rusting of coating surfaces by using graphic standards, including rust through coatings and visible bottom rust. The graphic standard is selected from the "European Rust Standard" published by the European Federation of Paints, Printing Inks and Artists' Color Manufacturers' Associations (CEPE) in Brussels. The ISO 4628-3-2017 also provides relevance to the ASTM D 610 rating system. This standard is suitable for evaluating various defects caused by rusting of coatings during aging and weathering, and helps to ensure the protective performance and aesthetics of coatings in actual use. The ISO 4628 series of standards covers multiple aspects of coating degradation assessment, including blistering, cracking, flaking, chalking, and more, and is suitable for a variety of application scenarios and material types.