Method for ink jet printing

A method of correcting velocity induced droplet placement errors in an oscillating bar drop-on-demand ink jet printer, which comprises:

• providing a row of drop-on-demand ink jet ejectors on a bar parallel to the long axis of said bar;
• providing a first and a second electrode, one on either side of each of said ink jet ejectors, and positioned between said ejectors in a line parallel to the long axis of said oscillating bar;
• providing direction and velocity sensor means for sensing the direction and velocity of movement of said bar;
• and
• providing direction and velocity control means responsive to said direction and velocity sensor means to control the application of electrical potential to the trailing electrode of said first and second electrodes to substantially completely compensate for velocity induced droplet placement error.