international etching, inc. (iei) manufactures custom metal components and finished metal products through the process of chemical milling on metals, also known as photo-etching.international etching can fabricate precise, intricate metal components from prototype to volume production. the etch, or chemical milling process, is fast, cost effective, and unmatched for design flexibility, intricate geometric features, and variable depths. the process is stress free and burr free. it induces no mechanical stress to the metal. all tooling is computer generated.