What is eighteen strokes in character sketch?

Eighteen strokes should not be the technique in figure sketch, but the traditional technique of figure painting in Chinese painting; It is 18 techniques of line drawing in Chinese painting. There are iron line drawing, olive drawing, flowing water drawing, jujube stone drawing, war pen water line drawing, pen reduction drawing, Liu Yemiao drawing, bamboo leaf drawing, mixed drawing, sticking head nail drawing, dead wood drawing, earthworm drawing, Gao Gu You Simiao drawing, string drawing, horse locust drawing, nail head mouse tail drawing, Cao Yi drawing, reed folding drawing, etc., which are used to express different textures of different objects and are mainly used for figure painting.