Slip-sheets meaning : (roofing) Sheet material, such as reinforced kraft paper, rosin-sized paper, polyester scrim or polyethylene sheeting, placed between two components of a roof assembly to ensure that no adhesion occurs between them and to prevent possible damage from chemical incompatibility, wearing or abrasion of the membrane. (shipping) A strong, thin pallet-sized sheet of plastic or fiberboard used to transport heavy items. A sheet inserted between freshly printed pages to prevent them from sticking together.