Chemical Etching Fabrication (Photofabrication): The production of precise metal shapes and other substances by reproducing a precise photographic image on the surface of the substance & etching away (or depositing upon) the unprotected areas by chemmachining or electrical means. Alternative Usage Terms: Photochemical Milling Definition photo chemical machining, electrochemical machining milling, chemical blanking process definitions: The precision removal from a thin metal sheet by etching or the conversion of material by electrochemical reaction. The chemmachining or milling process results in a very high tolerance with the parts being fabricated. Photochem, photoetch, photographic photo etching, photomill, photomilling, photomachining, process definitions: The precision removal from a thin metal sheet by etching. The photochem, photoetch, photoetching, photomill, photo etching / milling, or photomachining process results in a very high tolerance with the parts being fabricated.