D

dithering

The process used to fool the human eye into seeing more colors in an image than are really there. The process works by combining two or more existing colors into patterns. When viewed by the human eye, these patterns appear as solid colors.

dot gain

A measurement that describes and anticipates the way ink spreads and is absorbed on different kinds of paper. For example, ink spreads a lot more on newsprint than it does on glossy card stock, so you have to compensate to keep the dots from filling in completely.

duotone

A grayscale image that is tinted with one color for a graphic effect. Although duotones were originally designed to extend the tonal range of standard grayscale images, designers have embraced them for their graphic look and feel.