Fine porcelain, contemporary and antique, is marked on the underside or on an invisible spot with the name of the artist who made the piece or the factory that produced it. Marks often include signatures, initials, sigils, dates, and family shields. A mark may also be a stylized crown indicating a particular monarch who owned a porcelain factory, a symbol of a city, monarch or factory -- such as a lion -- or a printed, painted or impressed company name.
Famous examples of porcelain marks include the various identifiers for French Sevres pottery. Louis XV bought the Sevres factory in 1759 for its superior porcelain dinner and serving ware, vases, sconces and other products. The marks on these antiques include a cartouche of two crossed cursive "L"s enclosing a letter that stood for a date. Later, a crown or crowned eagle with the date denoted the royal pottery at Sevres.
Chinese marks were relatively rare before the Ming dynasty. Early Chinese porcelain marks from the Ming period include hand-lettered Kaishu, an unframed calligraphy. This style was followed in the 19th-century Qing dynasty by square red stamped seals with archaic Zuanshu characters.
Porcelain marks are incised, painted on bisqueware or added over the glaze.