A method of preparing a packaging laminate includes conveying a mesh of paper material having perforations against a rigid edge causing, at substantially each perforation, a mesh portion at the leading side to have an average elevation lower than that of a mesh portion on the trailing side of the perforation. The method includes expanding the perforations into cells separated from one another by legs interconnected by nodes defined in the mesh Top and bottom surfaces of the legs and nodes are reoriented from an initial orientation substantially parallel with a direction of conveyance of the mesh to an expanded orientation oblique to the direction of conveyance, such that, in the expanded orientation, the top surfaces of the nodes are substantially parallel with each other. The method includes attaching an outer liner to at least some of the bottom surfaces so as to form the packaging laminate.