A method and apparatus for the treatment of thin sheeting by subjecting said sheeting to a corona discharge. Two elongated electrodes are provided in a fixed spatial relationship. The first electrode is coated with a dielectric material and electrically grounded. The second electrode is machined to include a plurality of intersecting furrows which define a plurality of mesa structures, each having at least one acute angle corner. An electrical potential is applied to the second electrode and the sheeting material is then transported between the two electrodes. The mesa structures machined into the surface of the second electrode serve to enhance the amount of corona created by a given amount of electrical potential.