Measurement of the thickness of leather. 1 ounce = 1/64 inch = 0.4 mm. In theory this measurement is based on the assumption that one square foot of leather will weigh a certain number of ounces and will be a certain uniform thickness. Hence, one square foot of leather which would weigh 3 ounces theoretically would be a 3-ounce leather. However, in practice, this rule varies because of the specific gravity of diverse tanning materials used, and for that reason, a splitter’s gauge has been adopted to control the thickness of leather when sold by the square foot.

This definition is in context to Leather. See more contextual defintions for Ounce.