Some physical properties of leather which increase its value and durability in contrast to man-mades are: high tensile strength, resistance to tear, high resistance to flexual fatigue, good frictional properties under wet and dry conditions, controlled area stability, low bulk density, low conductivity of heat, large internal surface area, permeability to water vapor, moldability, resistance to water, resistance to fire, resistance to fungi, resistance to chemicals and resistance to perspiration.