What is “Mar”: blemish on the surface of a coating, extending over a particular area of the coating and visible due to the difference in the light-reflection properties of the area affected compared with the light-reflection properties of adjacent areas.

Mar resistance test for coatings is very similar with scratch resistance test, but this test uses arc（loop-shaped or ring-shaped）stylus to test the mar resistance of a single coating of a paint, varnish or related product, or the upper layer of a multi-coat system.

The product or system under test is applied at uniform thickness to flat panels of uniform surface texture. After drying/curing, the mar resistance is determined by pushing the panels beneath a curved (loop-shaped or ring-shaped) stylus which is mounted so that it presses down on the surface of the test panel at an angle of 45°. The load on the test panel is increased in steps until the coating is marred.

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. Kindly note this test does not specify a method using a pointed stylus, two of which are specified in ISO 1518-1 and ISO 1518-2, respectively. The choice between the three methods will depend on the particular practical problem.

BGD 536 Mar resistance Tester produced by Biuged confirms the newest international standard ISO 12137-2011, ASTM D 2197and ASTM D 5178. It can offer from 100g to 5,000g load to test panel.