Abstract: Methods and apparatus for supplying an ink mist to an electrostatic printing head or the like including means for continual replenishment, density monitoring, and density adjustment of the ink supply, and means for generating a highly uniform mist of ink droplets. An ion stream is modulated in accordance with images or characters to be printed. Ink mist is introduced into the ion stream. Ink particles impinged upon by ions become charged and are accelerated toward a receiving medium by an overall accelerating field. Ink not utilized by the printing mechanism is returned to the ink supply for recycling. The composition of the ink supply is regulated by means of continuous monitoring of the ink density; automatically controlling additions of the ink constituents functions to maintain the ink density at a given level. The ink recycling system includes a precipitator to convert the unused ink mist into liquid ink and air.