A pagewidth inkjet printhead is provided. The printhead comprises (a) a plurality of nozzles formed on a frontside of a substrate, each nozzle having a respective nozzle inlet; and (b) a plurality of ink supply channels. Each ink supply channel is configured for supplying ink from a backside of the substrate to a corresponding group of nozzle inlets. Further, each ink supply channel has an aspect ratio of less than 4:1, the aspect ratio being defined by the ratio of the channel depth to the channel width. A low aspect ratio allows facile backside etching of the ink supply channels.