Abstract: The invention provides a novel method of formation and structure of a slitted strip of metal, such a lead, which is to be expanded into a reticulated configuration. As applied to a battery plate, the invention contemplates the formation of a continuous strip of a lead or lead alloy material wherein the central portion of the strip which is to form the unexpanded current collecting top header portions of the finished battery plates is provided with a plurality of longitudinally extending punched apertures extending along the edge of the solid central portion and separating the solid central portion from slitted portions of the strip which are subsequentially expanded to form a reticulated grid. The formation of the continuous lead strip in such fashion substantially minimizes the "gull-wing" effect produced by the subsequent expansion of the slitted portions of the lead sheet.