Maeser Flex and Dynamic Absorption
Maeser flex is used to evaluate the ability of a waterproof material to remain waterproof when flexed in the vamp area. All waterproof leathers are subjected to this test, as are most other waterproof upper materials.
Dynamic Absorption is a measure of how much water is absorbed during simulated vamp flexing. This measure is indicative of the waterproofness of a material. The greater the waterproof, the lower the amount of water that gets absorbed during testing.