An ink jet apparatus having a scanning head employing at least one ink jet with a variable volume chamber which includes an ink droplet ejecting orifice, and a transducer, having a length mode resonant frequency, adapted to expand and contract along an axis of elongation in response to an electric field substantially transverse to the axis of elongation for ejection of droplets on demand from the ink droplet ejecting orifice is acoustically microstreamed by exciting the transducers during non-printing periods to eliminate start-up problems and to maintain pigments or other particles in dispersion within the ink.