Beadage.net tells us that leather is, "A versatile material created by tanning of animal hides and skin, usually cattle hide. Leather can be braided, used as a cord to string beads onto, or used as a base for bead embroidery." OrangeBridgeSupply.com tells us that, "Leather takes a certain amount of care to upkeep. Getting your leather [jewelry] soaking wet by wearing it in the shower or while swimming can strip the oils from the leather’s surface. If this happens, the leather can stiffen and even crack as it dries. It is all right to clean your leather bracelet if it gets dirty. Use a damp cloth to clean the leather, being careful not to scrub hard as this can cause any dust or dirt to scratch the surface of the leather."