A resistor card for a potentiometer to measure the fuel in a fuel tank consists of a non-conductive substrate with a plurality of elongate conductive contacts deposited. The contacts have an elevation above the surface of the substrate and the contacts are oriented in parallel relationship to each other to form a wiper track across which a wiper is movable. To reduce the rate at which the upper surfaces of the contacts are worn away by movement of the wiper, a non-conductive filler is deposited between the conductive materials which form the lands.