eggshell porcelain, Chinese porcelain characterized by an excessively thin body under the glaze. It often had decoration engraved on it before firing that, like a watermark in paper, was visible only when held to the light; such decoration is called anhua, meaning literally “secret language.”

Eggshell porcelain was introduced in the Ming dynasty during the reign of the emperor Yongle (1402–24). It reappeared in the reign of the emperor Chenghua (1464–87), and later Yongle wares were copied under the emperor Wanli (1572–1620). The paper-thin porcelain again occurred during the Qing dynasty (1644–1911/12), especially in the reign of the emperor Kangxi (1661–1722), in famille verte and famille rose porcelain, chiefly in bowls, plates, cups, and saucers. The manufacture of this porcelain is complex and time-consuming.