individuals and carved by artists, every seal is unique, and engravers often personalize the seals that they create. The materials of seals and the styles of the engraving are typically matched to the personalities of the owners. Seals can be traditional or modern, or conservative or expressive. Seals are sometimes carved with the owners' zodiac animals on the tops of the seals. Seals are also sometimes carved with images or calligraphy on the sides. Although it is a utilitarian instrument of daily business in East Asia, westerners and other non-Asians seldom see Asian seals except on Asian paintings and calligraphic art. All traditional paintings in China, Japan, Korea, and the rest of East Asia are watercolor paintings on silk, paper, or some other surface to which the red ink from seals can adhere. East Asian paintings often bear multiple seals, including one or two seals from the artist, and the seals from the owners of the paintings. East Asian seals are the predecessors to block printing. Western tradition There is a direct line of descent from the seals used in the ancient world, to those used in medieval and post-medieval Europe, and so to those used in legal contexts in the western world to the present day. Seals were historically most often impressed in sealing wax (often simply described as "wax"): in the Middle Ages, this generally comprised a compound of about two-thirds beeswax to one-third of some kind of resin, but in the post-medieval period the resin (and other ingredients) came to dominate. During the early Middle Ages seals of lead, or more properly "bullae" (from the Latin), were in common use both in East and West, but with the notable exception of documents ("bulls") issued by the Papal Chancery these leaden authentications fell out of favour in western Christendom. Byzantine Emperors sometimes issued documents with gold seals, known as Golden Bulls. Wax seals were being used on a fairly regular basis by most western royal chanceries by about the end of the 10th century. In England, few wax seals have survived of earlier date than the Norman Conquest, although some earlier matrices are known, recovered from archaeological contexts: the earliest is a gold double-sided matrix found near Postwick, Norfolk, and dated to the late 7th century; the next oldest is a mid-9th-century matrix of a Bishop Ethilwald (probably Æthelwold, Bishop of East Anglia). The practice of sealing in