柳体 refers to the calligraphic style of Liu Gongquan (
柳公权, 778-865), a Tang-dynasty master whose regular script (
楷书) is famously slender and steely — the saying
颜筋柳骨 (Yán jīn Liǔ gǔ — 'Yan's sinew, Liu's bone') contrasts him with Yan Zhenqing's (
颜真卿) more muscular style. Together with
颜体,
欧体, and
赵体,
柳体 is one of the four canonical regular-script models students copy.