The Contract Proof - 2000

Because continuous-flow printers are drum-based, they are expensive to build, and because a continuous flow of ink is required even when printing white areas (the unused ink is deflected into a drain), ink is a major cost.

Drop-on-demand ink-jet technology produces ink droplets only when needed, so no ink is wasted, and it is by far the faster of the two methods. Instead of varying drop size, dithering (variable droplet spacing) is used to achieve tonal variations.