Leather is usually sold by the square foot and is measured by special machines at the tanneries. The number of square feet is usually marked on the underside of the hide with a marker, chalk or machine stamp. Known as a skin, the complete hide of the animal may be left whole or cut into sections: sides, bellies, backs and shoulders.
The thickness (or weight) of leather is usually measured in terms of ounces. One ounce equals approximately 1/64" in thickness. Thus, 7-8 oz. means the leather is 7 to 8 oz. in weight or 7/64" to 8/64", making it approximately 1/8" thick. Lighter weight leather such as calf or kip (large calf) range from 1.5 oz. to 3-4 oz. Heavier leathers, 4-5 oz. to 10-11 oz. and more are from the hides of mature cattle.
To make leather a uniform thickness, the hides are run through a splitting machine. Since animal hides are not of uniform thickness and since they are wet when put through the splitting machine, the thickness of the leather will not remain the same throughout the hide. There will always be slight variations and that's why leather weights seldom measure out in exact 64th's of an inch. This is why leathers are usually shown as 4-5 oz.,
6-7 oz., etc.
Now that you have been introduced to the history of leatherwork, you are ready to begin to learn to create luxurious leather articles. Start with a billfold or key case. Soon you'll be making handbags, bowling bags, sporting goods, etc. Or, you may wish to begin your leatherwork hobby by making a pair of moccasins or sandals, or decorating your home with wall hangings and other accessories.
For centuries, leather has fulfilled a great need in man's life. So, full speed ahead. You'll be entering a fulfilling, creative hobby you'll enjoy all the years of your life.