The Kraft process is the world's predominant chemical pulping process. The name is derived from the German word for "strong." The method involves cooking (digesting) wood chips in an alkaline solution for several hours during which time the chemicals attack the lignin in the wood. The dissolved lignin is later removed leaving behind the cellulose fibres. Unbleached kraft pulp is dark brown in color, so before it can be used in many papermaking applications it must undergo a series of bleaching processes.