Abstract: A vector magnetic ink jet printer is arranged so that the ink droplets in the initial jet stream are alternately selected (i.e., magnetized) and unselected (unmagnetized). The interposition of unselected droplets between selected droplets prevents undesired magnetic interactions between selected droplets and gives them optimum spacing before they are deposited upon the recording surface, while at the same time keeping all of the droplets in sufficiently close proximity to give the stream aerodynamic stability. The gutter or catcher for unselected droplets is located between the second axial deflector (X deflector) and the recording surface. The magnetic field of the second deflector is specially shaped so that it can effectively control the trajectories of all selected droplets that have passed through the field of the first axial deflector (Y deflector), but without affecting the trajectories of unselected droplets aimed at the gutter.

Abstract: Improvements in water based magnetic inks of the type containing non-ionic, cationic and/or anionic surfactants by the inclusion of glycerol, non-volatile solvent such as mono-lower alkyl ethers of ethylene glycol and low molecular weight polyethylene diols.