Abstract: A mask formed by printing a pattern onto backing, and having firstly uninterrupted resist portions (3) suitable for withstanding a jet of abrasive material and secondly openings serving to allow said abrasive material to pass through, is placed in front of the piece (8). At least facing the openings, a material (16) suitable for etching porcelain or earthenware is blasted onto the mask so as to obtain one or more sunken relief pits of desired shape and depth. The piece obtained by implementing this method has deep, mat, and clearly marked sunken relief.