Leather armor

From the Book of War:

• 4.12.1.6. Leather: Armor constructed of tanned animal hide. Synthetic leather, pleather, or vinyl, and other man-made materials cannot be used in place of actual animal hides.
• 4.12.5.1. The minimum thickness for leather armor is 10oz (5/32", 4.0 mm).
• 4.12.5.2. The minimum thickness requirement can be achieved by layering up to two (2) pieces of thinner leather.