CMYK stands for Cyan, Magenta, Yellow and Key (or blacK)—the colours that are used in four-colour process printing. Overlapping dots of cyan, magenta, yellow and black produce the full spectrum of reflective colour found in photographs. Colours for type and graphics can be made from combinations of these colours as percentages. For example, 100 percent yellow and 50 percent magenta makes orange, or a mixture of cyan and yellow makes green. In the printing process, the screen for each colour is printed at a different angle to improve print quality and reduce moiré patterns. In book design, a fifth black plate is often used for text, because if the book is published in several languages, only the black text plate needs to be changed.