|Crafts and Trade|
Iron and all the non-ferrous metals were worked with a high degree of skill in the 11th - 12th centuries.As far as iron is concerned, however, it was not possible, as it is today, to heat a furnace to a sufficiently high temperature either to smelt it from its ore or to cast it into objects by making it molten. Each iron object had therefore to be forged individually by a blacksmith. One of the smith's greatest skills was the ability to introduce small amounts of carbon into iron to make steel which was used in the production of tools and weapons. Iron was also used to make the body armour and horse equipment which were becoming increasingly sophisticated in this period. Another of the blacksmith's specialities was locks and keys and on occasion his artistic ability was allowed full expression in the decorative straps and hinges on church doors and chests.
The non-ferrous metals, including silver, copper and lead, could be heated to melting point and were therefore extracted from their ores in a fairly pure form. They could also be cast in moulds allowing the replication of objects on a large scale. Such objects included small day-to-day items like buckles and rings, but it was also possible to achieve elaborate three dimensional effects and some of the bronzes of the period, such as the Gloucester candlestick, are artistic achievements of the highest order.Casting employed the lost wax method in which a wax model of the intended product was covered by clay to form a mould which was then heated to melt the wax. After the wax had been poured away, the metal replaced it in the mould and took on the form of the model.
Decorative treatment of metalwork included gilding and the use of niello, a black compound made of silver and lead or copper. Champlevé, involving heating powdered glass to fill panels on the surface of an object is also known.