MASTE leather articles are made using leather tanned with natural processes (vegetal) only.

Vegetable tanning: a traditional process relying only on time and natural products to turn crude skin to leather. The process begins with the preparation of crude skin to absorb the tanning substances. Among these the most important is tannin, a natural product extracted from the bark of trees. The skin then spends forty days in great wooden barrels (called "bottali") and it slowly becomes natural leather, whose characteristics are softness, strenght, smell and looks yet unequaled by industrially processed leather.