Continued investigations of the thermoelectric properties of Au&sngbnd;Ni thin‐film thermocouples have been made. The thickness dependence of the Seebeck coefficient for Ni films of variable thickness on bulk Au was determined and found to be sensitive to the thermal history of the thin film thermocouples. By developing suitable preparation techniques for these thermocouples, involving several periods of annealing, time‐invariant calibration curves were obtained. The thickness dependence of the Seebeck coefficient was found to follow closely the predictions of the size‐effect theory of Mayer.