embossing or engraving - An embossing or engraving nip where the surfaces of the two rollers are perfectly matched, so that wherever the surface of one roller is raised by some distance, the corresponding surface on the other roller is recessed by the same distance. When the rollers are fully engaged, there is complete contact at every point along the nip line. In matched embossing, both rollers are engraved (as in steel-to-steel embossing), and one roller is usually made from the other in a matched steel engraving process using acid etching. In actual embossing practice, absolutely perfect matching is often avoided, in order to improve runnability, by creating a small gap between the rollers in selected areas of the pattern.