A thermal ink jet head incorporates bubble-generating resistors, each with a relatively thick layer of unpassivated resistive material, such as TaAl. The thermal ink jet head includes an ink source, ink channels, respective orifices, and circuitry for providing the electrical energy which the resistors convert to heat to form bubbles which expel ink through respective orifices. A range between 3,000 .ANG. and 5,000 .ANG. is preferred for the resistive material to minimize failure rate while avoiding thermal, electrical and manufacturing limitations of passivated resistors.