A resistor array formed by the process of forming a plurality of holes or grooves in an electrically insulating substrate, filling the holes or grooves completely with a flowable, electrical resistance material, and then hardening the resistance material. The resistance material can be comprised of an electrically non-conductive thermally setting base material throughout which electrically conductive particles are dispersed, or the resistance material can be colloidal or a suspension. The value of the resistors is determined by the volume resistance of the resistance material and the volume of the holes or grooves, the resistance increasing as the length of the holes or grooves increases and decreasing as the cross-sectional area of the holes or grooves increases. A resistor array having leadless terminals is provided by sandwiching the insulating substrate between layers of electrically conductive material and forming the holes or grooves through at least one of the layers of electrically conductive material and the substrate, and then filling the holes or grooves with the resistance material.