A method comprising: providing a transparent electrically conductive film comprising: a transparent substrate (14); a composite layer (18) comprising: an electrically conductive layer disposed on at least a portion of a major surface of the transparent substrate (14) and comprising a plurality of interconnecting metallic nanowires (12); and a polymeric overcoat layer disposed on a portion of the electrically conductive layer, to provide a coated area of the electrically conductive layer; and patternwise exposing the coated area of the electrically conductive layer to a corona discharge to provide a patternwise exposed electrically conductive film comprising (1) an un exposed region (122) of the coated region having a first electrical resistivity, and (2) an exposed region (121) having a second electrical resistivity; wherein the exposed region is less electrically conductive than the unexposed region, and wherein there is a ratio of the second electrical resistivity over the first electrical resistivity of at least 1000:1.