USA Vegetable tanned, full grain leather. Vegetable tanned leather is an old-world, artisanal process that uses tannic acids naturally found in some plant species, by using the barks, branches, leaves and even some fruits in some specific techniques. Full Grain leather is the highest quality leather. This layer of the hide includes ALL of the natural grain and isn’t sanded or refinished. Full Grain leather is extremely strong and durable, as the natural grain contains the strongest fibers in the hide. The leather will age, rather than wear out, developing a much sought-after patina and unique character.