Slip joint knives are the type of knives your grandpa used to carry around. They do not lock, but instead have a spring that biases them towards being open or closed. They can have one blade or multiple blades. Common traditional slip joint knife patterns are the Barlow, Butterbean, Canoe, Congress, Copperhead, Equestrian (or Horse Knife), Hobo, Hunting, Muskrat, Pen knife, Peanut, Pruner, Sodbuster style knives, Stockman, Texas toothpick (AKA Tickler or Fish Knife), Trapper, and Whittler. A.G. Russell Knives, Boker, W.R. Case, Cattlemen Cutlery, and War Eagle Blades all produce traditional knife patterns. Slip joint knives can also be modern, sometimes even with a pocket clip. Benchmade and Spyderco are two modern knife companies that product modern slip joint knives. These are referred to as Modern Traditionals.