Inksticks (Chinese: 墨 ; Japanese: 墨 Sumi; Korean: 먹 Meok) or Ink Cakes are a type of solid ink (India ink) used traditionally in several East Asian cultures for calligraphy and brush painting. Inksticks are made mainly of soot and animal glue, sometimes with incense or medicinal scents added. To make ink from the inkstick, it has to be continuously ground against an inkstone with a small quantity of water to produce a dark liquid which is then applied with an ink brush. Artists and calligraphists may vary the thickness of the resulting ink according to their preferences by reducing or increasing the intensity and time of ink grinding. Along with the inkstone, ink brush, and paper, the inkstick is considered in one of the Four Treasures of the Study of classical Chinese literary culture.