Abstract: In a continuous electrolytic foil forming process employing a constant d.c. voltage power supply, the speed with which the foil is drawn through the electrolyte is automatically adjusted by a feedback mechanism to maintain a constant value of forming current. In this process, the speed of drawing the foil corresponds inversely to the potential capacity of the foil as it enters the electrolyte at any given time. This speed or equivalent capacity and the corresponding location of the foil is monitored and recorded during the continuous film forming process.