I like nylon leashes for running/traveling because of how light they are. But for day-to-day walks and for training in general, I prefer the heft of a leather leash. It takes some time to break in, but the weight and feel of the leather helps give you and your pup a much stronger awareness of where each other are. Plus, leather is easy to clean and should last forever. The place I bought my leashes no longer sells them, but I really like Saddlebackâs stuff too.