A modular printhead includes an elongate extrusion defining internal passages for carrying air, ink and fixative. The extrusion further defines repeated patterns of holes along its length with each pattern having holes in fluid communication with respective passages. A plurality of printhead modules is serially engaged along the extrusion with respective patterns of holes. Each printhead module defines inlets aligned in fluid communication with respective holes and internal chambers in fluid communication with respective inlets. Each printhead module includes an ink ejection integrated circuit (IC) which is fed the air, ink and fixative from the internal chambers.