There are two different types of materials used....body webbing and anti-squeak. Body webbing is a flat, wide woven material that is used between the frame and the body, and anti-squeak is a black shiny material with a round bead on one edge and it is used between the fenders and the body and etc.
For example, the body webbing is used on the frame rail and then the running board splash aprons sits on top of the webbing. The black anti-squeak with the bead is used in such areas as between the rear fender and the body, between the front fender and the running board splash apron, between the running board and the front and rear fenders and etc.
