1 This part of ISO 12137 is one of a series of standards dealing with the sampling and testing of paints, varnishes and related products.
It specifies a method for determining, using a curved (loop-shaped or ring-shaped) stylus, the mar resistance of a single coating of a paint, varnish or related product, or the upper layer of a multicoat system. Part 2 of ISO 12137 specifies a method using a pointed stylus. The choice between the two methods will depend on the particular practical problem.
2 This test has been found to be useful in comparing the mar resistance of different coatings. It is most useful in providing relative ratings for a series of coated panels exhibiting significant differences in mar resistance.