Leather… it's an amazing material.
The proper stuff anyway. We're not talking about camel skins dried under a hot sun and then drenched in sunflower oil. Real, good, proper leather, tanned using the old traditional European methods, goes through over 20 stages to make it tough, flexible and long-lasting. The actual tanning stage is done with vegetable extracts and tree bark which contains the natural substance tannin. Steeping the leather this way takes months, sometimes years. In the 1840s, tanning was updated using chromium salts. Not only is this a faster and cheaper process, it also makes a more waterproof leather that's often tougher too. Most leather goods are made from this.