METHOD OF MULTI-TONE PRINTING

A method of multi-tone printing employs a drop-on-demand printing apparatus 100 for depositing ink droplets from an array of channels 104 on printing element areas of a substrate 111 which is movable relatively to said apparatus. The channels length and nozzle location and dimensions afford each channel with a high longitudinal resonant frequency and electrically actuable means 110,112,114,116,118 supply energy pulses to a selected band of channels at or near the resonant frequency of the channels to deposit from each selected channel in the corresponding printing element area of the substrate a number of drops equal to the number of pulses applied thereto, the number of pulses applied being dependent on the tone of printing required. Droplet ejection from even numbered channels is in anti-phase at the resonant frequency with droplet ejection from odd numbered channels.