Use of terracotta as a building material took off in the UK in the 1860s, when architects, realising how rapidly stone buildings would decay, took inspiration from Renaissance buildings in Italy.
In Italy, terracotta has preserved buildings for 400 years, protecting them from the effects of pollution and providing a cheap method of producing multiple decorative ornaments.
Alfred Waterhouse created the Museum’s distinctive blue and beige colour scheme by tinting the terracotta clay with ground slate before it was fired. A shortage of materials meant he had to cut back on the amount of blue.
Air pollution in London from Victorian times onwards left its mark on this building. After various attempts to find a cleaning method that did not damage the terracotta’s shiny surface, in 1974 steam was used to restore the building to its former splendour.
Terracotta is moulded like clay, using statues to form plaster moulds into which the liquid clay is poured. Once dried, these are then fired in a kiln to form the finished ornament.