The two pins on the left are typical of threadless pins for threadless insulators. These two examples did not have any type of additional material to secure the insulator. The two pin tops at the right are examples of materials used to secure the insulator to the pin. The white colored one has a wrap of gauze-like fabric which is coated with a white paste similar to pipe caulk. The one on the far right is covered with a fine burlap cloth material. This example appears to have been coated with a red lead compound.