In a print cartridge according to the preferred embodiment of the invention, a polymer tape having orifices formed therein and containing conductive traces has a substrate containing heater elements affixed to a back surface of the tape. Each of the heater elements in the substrate is located substantially behind each of the orifices. The edges of the nozzle member overlap the edges of the substrate, and the back surface of the tape is sealed with respect to an ink reservoir so that a seal substantially circumscribes the substrate. This allows ink to flow around the side edges of the substrate and into vaporization chambers associated with each orifice. The conductive traces on the tape are attached to electrodes along the shorter side edges of the substrate so as not to interfere with the edge-feed of ink along the longer edges of the substrate. A demultiplexer on the substrate requires relatively few electrodes to be formed on the substrate for supplying energization signals to the numerous heater elements formed on the substrate.