engrave (metal, glass, or stone) by coating it with a protective layer, drawing on it with a needle, and then covering it with acid to attack the parts the needle has exposed, especially in order to produce prints from it
aquatint is a process of achieving tone by etching a metal plate
(of an acid or other solvent) corrode or eat away the surface of (something)
caustic soda etches glass
tiny droplets in the glaze emulsion were etched away by acid