Sometimes rough surfaces are turned to smooth surfaces by adding material. For example, adding lacquer to wood. Any word for this process or its result?
The verb is "to finish":
complete the manufacture or decoration of (a material, object, or place) by giving it an attractive surface appearance. "the interior was finished with V-jointed American oak" synonyms: varnish, lacquer, veneer, coat, stain, wax, shellac, enamel, glaze "some items were finished in a black lacquer"
finish is also a noun, referring to the end result of the process of finishing.