a plastic packaging material which , when formed as a package having seams , will provide a predictable line of failure along a seam when the package is opened to prevent the package from tearing down the side . the predictable failure path is provided through a lamination process involving specific resins or blends of resins laminated in three layers in which an extruded inner layer forms a weak inner bond wholly within that inner layer to create the predictable line of failure and in which the process of forming the material does not inhibit processing speed , efficiency , and economics of materials used to provide this reliable openability .