A black liquid used for calligraphy and painting, sumi developed in ancient China along with writing brushes (fude). Made from soot that is collected when burning oils or woods and mixed with a binder like animal glue, sumi is formed into ink sticks and allowed to dry. To release the coloring, the stick is rubbed against an ink stone (suzuri) into a small pool of water until the desired intensity is achieved. Nara period inksticks were often boat-shaped and pointed at both ends.