This type of natural tanning proses uses tannin extracted from plants (mimosa, chestnut, quebracho, tara, etc etc). Vegetable tannage is a very old procedure dating back to prehistoric period, a very slow process wich is considered an art. The formulas used by each tuscan tannery is a well kept secret, a result of a careful blending of Tuscan culture and knowledge, passed down through the years from father to son.