NBN EN ISO 20433:2012

This International Standard specifies a method for determining the amount of colour transferred from the surface of coloured leather to other surfaces by rubbing with a white cotton cloth.
Two tests are carried out, one with a dry rubbing cloth and one with a wet rubbing cloth.
The method is applicable to all types of coloured leather. Since after treatments of the leather as well as surface finishes can affect the degree of colour transfer, the test can be made before and/or after such treatments.