GB/T 39373-2020 standard for leather colour fastness testing, focusing on solvent resistance colour fastness. The standard specifies the testing process of leather solvent resistance colour fastness, and stipulates the type, concentration, action time of solvents used in the test, as well as the treatment of leather samples and the evaluation of colour fastness. Accurate inspection of leather Color Stability by simulating the actual situation of leather contact with various solvents. This provides mass assurance basis for leather products in use scenarios where they may be exposed to solvents, and helps enterprises produce leather products with better performance.