Biothane is a synthetic material that has become increasingly popular for use in collars and leashes for big dogs. It offers several advantages over traditional leather, such as its durability, waterproof, and low-maintenance features. Biothane is resistant to wear and tear and abrasion, and does not require any conditioning or oiling, making it easy to clean. It also doesn't absorb odors or bacteria, and it is lighter weight than leather. Additionally, it is UV resistant and have a good grip, making it great for outdoor activities. Biothane is a great option for big dogs that are rough with their gear or that enjoy playing in the water, due to its resistance to water. It is also a comfortable and safe gear option for big dogs, as it is less likely to stretch or snap like a traditional leather leash.