One of the tests for determination of colour fastness of dyed of printed leather is the crocking test. This test is used for the determination of colour fastness against rubbing, either under dry or wet condition. In this test, a moving brass finger of specified shape and size rubs against the test specimens under a fixed load. The amount of colour lost by the test specimen and the amount of colour transferred to a piece of abradant Leather fixed over the base of the moving finger are graded with the help of standard grey scales to evaluate the colour fastness of the sample under test rubbing.
- Diameter of Rubbing Finger: Less than 16 mm
- Force on rubbing finger: 9N ( 917.43 g)
- Size of test specimen: Less than 250 x 50 mm