Vegetable tanning uses bark, leaves and branches from trees and plants to add natural tones to the leather. The tanning involves a gentle process over several weeks of treatment that allows the leather to age better and last longer than chrome-tanned leather. The natural process means that the leather will develop a rich patina with use, so your wallet actually looks better over time. Each piece made with this natural leather has its own unique shades & nuances, making your wallet uniquely yours.