A printhead (1) for a continuous ink jet printer has a single pair of nozzles (3,3'). One or more oscillators for vibrating the ink (3,3') may be used to break up the twin streams (4,4') of droplets issuing from the nozzles. A pair (5) of charging gates is provided for applying, selectively and respectively, a charge to droplets in the two streams (4,4'). A pair of deflector means (7) apply respective electric fields across the streams (4,4') to deflect the droplets individually in accordance with the charge thereon. A gutter (10) or pair of gutters (11,11') receive droplets from the respective streams if they are not charged. The arrangement is such that the two streams of droplets are deflected in opposite directions so as to be printed.