Sexual designs were used for porcelain ware by the Manchu emperors such as Ch’ien Lung and Hsien Feng, as a form of sexual elaboration. Erotic motifs and designs were used on vases, bowls, plates etc.; it has been established that such designs were painted on earthenware in the first and third centuries. One early Chinese habit was to bury earthen bowls and plates where “future rebel leaders or rulers might be born.” It was thought that earthenware carrying erotic designs would bring ill luck to future rulers and thus forestall possible uprisings.