An inkjet printer that has a plurality of nozzle apertures, each with a nozzle axis normal to, extending through the center of the nozzle aperture. A chamber corresponds to each of the nozzles respectively. An inlet to supply the bubble forming chamber with liquid. A heater element is disposed in each of the bubble forming chambers respectively. The heater element configured as a beam suspended at its ends for immersion in the liquid such that heating the heater element forms a gas bubble that ejects a drop of the liquid through the nozzle corresponding to that heater element. The heater element is a planar structure parallel to the nozzle aperture and nucleates the gas bubble with a bubble centre offset from the nozzle axis towards the inlet. Offsetting the gas bubble towards the inlet reduces the variation in drop trajectories caused by reverse flow out of the inlet when the pressure pulse is generated.