An elongate strip (10) is disclosed which can be manipulated into a cylindrical shape to form a casing for a food product. The strip comprises films of synthetic plastics material which are laminated together. One of the two outer films of the laminate is a peelable ionomer and the other is an olefin. A plurality of web weakening formations (18) for facilitating initiation of transverse tearing of the web are provided along one of the longitudinal edges of the web. The formations constitute the boundaries of a plurality of pull tabs (20). The weakening formations can be lines of perforations extending inwardly from said one edge of the web