The most common method of etching is called photochemical etching. In this process, the material is cleaned and then laminated with a UV-sensitive photoresist. A photomask is created by printing the artwork as a negative onto a clear piece of film. The photomask is placed on top of the material in an exposure unit, and a vacuum is drawn to ensure contact between the phototool and the metal plate.
The plate is then exposed under UV light that allows the areas of resist that are in the clear sections of the film to be hardened. After exposure, the plate is “developed,” washing away the unexposed resist and leaving the areas to be etched unprotected.
-Liam Dullaghan Jr., MasterEtch
