Embodiments of the disclosed subject matter provide methods and systems including a nozzle, a source of material to be deposited on a substrate in fluid communication with the nozzle, a delivery gas source in fluid communication with the source of material to be deposited with the nozzle, an exhaust channel disposed adjacent to the nozzle, a confinement gas source in fluid communication with the nozzle and the exhaust channel, and disposed adjacent to the exhaust channel, and an actuator to adjust a fly height separation between a deposition nozzle aperture of the nozzle and a deposition target. The adjustment of the fly height separation may stop and/or start the deposition of the material from the nozzle.