Heo Mok (許穆, 1595-1682), a Neo-Confucian member of the literati, a politician, and an artist of the mid-Joseon Dynasty, was also a noted calligrapher. He deeply scrutinized the ancient Chinese style of calligraphy known as “seal script,” whence he eventually developed his own unique style. This book handwritten by him contains ancient seal scripts gathered from many kinds of epigraph according to their rhymes. This can therefore be called a dictionary of ancient seal script.