The uppers of shoes get folded over the toe portion every time a step is taken. These repeated folding cause the finished grains to start cracking, resulting in loss of water resistance. To ensure that the leather uppers retain their water resistance for a reasonable period of use, the action of such folding on them is simulated by subjecting test specimens taken from the leather to a water penetration test using a electrometer.

In this test the test specimens are held in form of thoughts between two cylindrical grips one of the grips is then repeatedly moved towards and away from the other along their common axis .the test specimens are kept immersed in a water bath unto a part of their periphery. Penetration is detected when electric conductivity is established between the inside and outside surfaces of the test specimens.