Ink wash painting, also known as in Chinese shui-mo hua (水墨畫), in Japanese sumi-e (墨絵), in Korean sumukhwa (수묵화), and in Vietnamese tranh thuỷ mặc (幀水墨).
Ink wash painting uses tonality and shading achieved by varying the ink density, both by differential grinding of the ink stick in water and by varying the ink load and pressure within a single brushstroke. Ink wash painting artists spend years practicing basic brush strokes to refine their brush movement and ink flow. In the hand of a master, a single stroke can produce astonishing variations in tonality, from deep black to silvery gray. Thus, in its original context, shading means more than just dark-light arrangement, it is the basis for the beautiful nuance in tonality found in East Asian ink wash painting and brush-and-ink calligraphy.