Art metal-work; Enamel and enameling; Goldwork; Metal-work; Silverwork; metal materials; metal tools; soldering; filigree; setting stones; raising; shaping; spinning; repousse work; wire twisting; metal hinges; metal joints; inlaying; overlaying; niello; alloys; stratified fabrics; enamelling; cloisonne; plique-a-jour; champleve; bassetaille; encrusted enamel; painted enamel; metal casting; construction; metal polishing; metal coloring; metal assaying