The most lavish medieval books were bound in covers set with enamels, jewels, and ivory carvings. Book Cover Plaque: Christ in Majesty, ca. Made in Limoges Gilded copper and champlevé enamel Source: Book Cover Plaque: Christ in Majesty [French]
Not the right place to pin this, but do not want to forget Anonymous: Angels, Saints and the Four Evangelists Book-cover ca. 1506 (The Book of the Gospels) Silver-gilt x cm The British Museum London, UK Inv.