GB/T 9279-2007 "Paints and varnish scratch test" proposed by China Petroleum and Chemical Industry Association aims to determine the scratch resistance of Paints and varnish coatings to hemispherical needles under standard conditions. The standard is applicable to the test of single-layer and composite coating systems, and the scribing needle can penetrate to the substrate or intermediate coating. The main uses include two aspects: 1) as a "pass/fail" test, applying a specified load to assess whether the coating meets specific requirements; 2) by gradually increasing the load to determine the minimum load of the penetrating coating. This standard provides an important reference for the evaluation of coating performance.