Bokashi (Japanese: ぼかし) is a technique used in Japanese woodblock printmaking. It achieves a variation in lightness and darkness (value) of a single color by hand applying a gradation of ink to a moistened wooden printing block, rather than inking the block uniformly. This hand-application had to be repeated for each sheet of paper that was printed. The best-known examples of bokashi are in the 19th-century ukiyo-e works of Hokusai and Hiroshige, in which the fading of Prussian blue dyes in skies and water create an illusion of depth.