A printhead assembly includes a printhead which, in turn, includes a molding. The molding defines a recess in which an integrated circuit (IC) configured to eject ink can be received. The molding defines a quartet of separate ink passages each in fluid communication with the IC. An elongate support member supports the printhead and defines a quartet of separate ink reservoirs each in fluid communication with a respective ink passage. The support member includes a core element which defines the ink reservoirs and a metal shell in which the core can be received.