Print head or ink jet printer with reduced solvent consumption

A print head of a binary continuous jet printer comprising: a plurality of nozzles for producing a plurality of ink jets in a cavity delimited by lateral walls, an upper wall and a lower wall, a sorting unit for separating drops or sections of one or more of the jets intended for printing from drops or sections that do not serve for printing, a slot, which passes through the lower wall, enabling the exit of ink drops intended for printing, a gutter for recovering drops or sections not intended for printing, a conduit for injecting gas into the cavity, and for making this gas circulate, in the cavity, to the plurality of nozzles for producing a plurality of ink jets in the cavity, then to the gutter.