Lining material for the internal of a case, designed to be a rust inhibitor. Tri-Wall: Heavy duty cardboard sheet (stronger than Double Wall) used to construct carton that is fixed to a pallet base - providing alternative to timber case.
Tar paper is a heavy-duty paper used in construction. Roofing felt is one type of tar paper. Tar paper is made by impregnating paper with tar, producing a waterproof material useful for roof construction.