One embodiment of the invention includes a method for imparting a unique identifier to a molded polymeric article. The method includes providing a label comprising indicia having a thickness effective for embossing the polymeric article during molding and a melting point greater than the melting point of the molded polymeric article. The method also includes attaching the label to the article prior to vulcanization. The method further includes vulcanizing the article so that indicia emboss the molded polymeric article by forming indentations in the molded polymeric article.