They were never one fixed group of eight: Qing and later writers list up to fifteen names. The usual list includes
金农,
黄慎,
高翔,
郑燮 (better known as
郑板桥) and
罗聘. They sold to the rich salt merchants of the city, and
怪 'odd' refers to their break with the orthodox court style, not to their characters.
