Manufacturing method and apparatus

An etching system (1) comprises a host PC (20) which stores a bitmap etching pattern (210) and transmits this via its own interface (200) and a data link (30) to an etching apparatus (10). The etching apparatus (10) includes its own interface (170) which receives the bitmap etching pattern (210) and passes it onto a control unit (110). The control unit (110) generates control signals for an etching head driver (120) which in turn drives an etching head (130) to eject etchant from an etching reservoir onto an item to be etched. The etching head (130) is moved relative to the item to he etched by means of motors (151, 152) which are driven by motor drivers (141, 142) which are also controlled by the control unit (110). The etching head (130) selectively deposits droplets of etchant onto the item to be etched in such a way that unwanted portions are removed by the droplets of etchant whilst wanted portions are maintained intact.