The main difference is the thickness and stiffness of the leather.  Bullhide (1/4") Max Thickness is 14+ ounce leather. It has stiffer qualities and is a great casual, work, or gun belt.  Bullhide (3/16") leather is 10-12 ounce leather and is more of a casual or dress thickness belt. We do offer a few 1/8" thick belts which is similar to the thickness a store sells.  Normally the thicker the belt the more durable the leather.  If you want a heavy duty thicker belt you would go with the 1/4" thick but if not go with the 3/16" thick.  Please note that thickness of leather is approximate since these are natural hides and can vary slightly from hide to hide.