His wares all start here, with top-grade, 5-ounce cow leather which he buys by the truckload from a ranch in Wisconsin. Full-grained leather — which is thicker and nicer than most leather that's been split in half — starts at $2 per square foot. His leather is tanned just for him using a special formula and costs $8 per square foot, which is why his medicine balls have proven too expensive to wholesale. Chrome-tanned leather of this kind is also used for baseball gloves, and since it hasn't been dyed or sealed, you can oil it to keep it soft and supple.