The type of leash you use in your dog training program will be based on a few different factors. I often two leashes at the same time. Normally a long leash that trails behind the dog and a shorter leash I use to hold in my hand while training. Once the formal part of the lesson is complete, I remove the short leash and the long leash is already on and ready to go for the play session. Everything you do in your training sessions gets into the pattern of learning, so if you remove one leash then put another one on your dog remembers each. By practicing with two leashes one your dog forgets the second one, so when you take off the short training leash it simulates freedom to your dog while insuring you have control in case you need it.
The different materiasl commonly used for dog training leashes are cotton, nylon or synthetic and leather. Leather is by far the best material because it is long wearing and comfortible to handle.
Safety leashes are the second leash. They are your backup line and simulate freedom at the end of a formal training session. These consist of of a long line. I normally use a least a 33 foot leash. Some environments require a shorter one like a 18 or 20 foot line (like a small training yard). These leashes you normally do not need leather since they are used to drag on the ground.
Basic Training Leashes
The basic training leash is 6 feet in length. No shorter or longer. The reason is that some skills require us to move away from the dog and normally 6 feet is the perfect length to perform these tasks.
Drag Leashes - Around The House Leashes
These are the 4 foot models. They are use to drag around the house of environments that are close quarters. They serve as a tool to stop unwanted behavior in and around the house. A 4 foot leash normally will not tangle around furniture or other items in the house like a 6 foot leash would.
Advanced Training Leashes
These leashes include the shortest versions of leashes. The advanced dog can wear a 4 foot leash for training. The tab leashes are normally about 6 inches in length and serve as a handled to reach for to help the advanced dog remember that you are still in control.