In Chinese, Japanese and Korean painting, the personal chop or seal establishes the artist’s identity and is used to authenticate the painting. This authentication seal is the artist’s signature, which when also written serves only as a secondary identification. The artist also may use mood or side seals to convey transcendent themes. In ancient China it was customary for each successive owner of a painting to add his own personal seal to that of the artist. This custom provides a valuable history of the work and accounts for the proliferation of seals found on old master paintings. In those dynastic days, only persons of great privilege, wealth, and position could own or sponsor such works of beauty.