their survival rate and portability were very important in the transmission of artistic style, especially in Carolingian art, which copied and varied many Late Antique ivories. African elephant ivory became increasingly available in Europe from the 13th century, and the most important centre of carving became Paris, which had a virtually industrial production and exported all over Europe. Secular pieces, or religious ones for lay-people, gradually took over from production for the clergy. Mirror-cases, gaming pieces, boxes and combs were among typical products, as well as small personal religious diptychs and triptychs. The Casket with Scenes of Romances (Walters 71264) is an example of a small group of very similar boxes, probably presented by a future bridegroom to his future wife, that brings together a number of scenes drawn from medieval romance literature. The supply of African ivory contracted greatly in the later 14th century; one result was a rise in bone carving for "marriage caskets", mirror, and religious pieces. The north Italian Embriachi workshop led this trend, supplying bone carvings even to princes and the extremely wealthy; when they used ivory it was usually hippopotamus teeth. Though the supply improved from the 16th century, ivory was never so important after the end of the Middle Ages, but continued to be used for plaques, small figures, especially the "corpus" or body on a crucifix, fans, elaborate handles for cutlery, and a great range of other objects. Dieppe in France became an important centre, specializing in ornate openwork and model ships, and Erbach in Germany. Kholmogory has been for centuries a centre for the Russian style of carving, once in mammoth ivory but now mostly in bone. Scrimshaw, usually a form of engraving rather than carving, is a type of mostly naïve art practised by whalers and sailors on sperm whale teeth and other marine ivory, mainly in the 18th and 19th centuries. Ivory was used for the balls for table ball games such as billiards and snooker until the late 19th century, even as they became far more widely played. Other uses were for the white keys of keyboard instruments and the handles of cutlery, sometimes elaborately carved. Islamic World Ivory is a very suitable material for the intricate geometrical patterns of Islamic art, and has been much used for boxes, inlays in wood and other purposes. From 750 to 1258 A.D., the Islamic world was more prosperous than the