electrotyping also known as galvanoplasty uses electrolysis to accurately reproduce a copy in metal any object with an irregular surface. A mould is taken from the object to be copied and is made electrically conductive with a layer of graphite powder or conductive paint. A link is made between the surface of the mould and the negative pole of the rectifier (cathode). The mould is suspended in the electrolyte when power is applied the copper ions are dissolved from the anode build up on the conductive surface of the mould.