Treated leather is a type of leather that has been processed with chemicals and oils to make it more durable and resistant to water and other elements. TANNED leather is the first step in this process, where the hide is soaked in a solution of tannins, which are natural compounds found in plants, to preserve the hide and make it more pliable. After the tanning process, the leather is then treated with oils and waxes to give it a protective coating and to make it more resistant to wear and tear.