Sculptures can be made of many different materials, and can be either free-standing or set into the material of a building as architectural sculptures. For free-standing sculptures, bronze is one of the most popular metals used for casting works from antiquity to the modern-day. The tenth and eleventh centuries saw monumental works in bronze, particularly for church decoration, become popular. Doors were cast for cathedral churches, reminiscent of the bronze doors for Aachen Cathedral thought to have been created during Charlemagne’s reign. Columns and enormous candelabras cast in bronze were also created for tenth and eleventh-century monasteries and cathedrals.
Bronze could be decorated with relief sculpture, where figures project forward from the background; this decoration was first carved in a soft material, either clay or wax, which was then used to create a mould into which liquid bronze was poured (cast). This is the form used for the magnificent bronze relief sculptures at Hildesheim in the early eleventh century.
Other sculptures were created in stone, alabaster, wood or precious materials, often adorning the surfaces of churches. The stone walls and column capitals of a church could be decorated with carvings of biblical scenes, animal, floral, or other motifs, ranging from elaborate, finely detailed designs to more simplistic decoration. Free-standing sculptures in wood or precious metals, such as the Golden Madonna of Essen or the Gero Crucifix, became more popular in the later half of this period.