Metallic glazing is a highly specialised decorative technique which produces gold or ruby colouring with opalescent or iridescent shading. This sophisticated process was adopted by potters in the second half of the 15th century, almost certainly thanks to the Moresque lustreware being imported from the Spanish port of Majorca, which accounts for the name maiolica. Among the principal chemicals required in this technique are silver oxalate and silver nitrate, copper oxide and copper sulphide, as well as other oxides, which are then diluted in a solution of clay and vinegar. Following the application of the resulting paste on the painted pots a third firing takes place at 620°C, known as piccolo fuoco (low flame), which is produced by using types of firewood capable of maintaining low temperatures and reducing the presence of oxygen and moisture inside the kiln. The characteristic metallic glazing is not immediately visible as it is covered by the hardened clay solution but its glorious luminescence is revealed after wiping the object  with a cloth. The first pottery producing centres in Italy to experiment with this technique were Faenza, Pesaro, Deruta and Gubbio but it took root especially in the two Umbrian towns, where it developed into a systematic  production of world renown. Metallic glazing arrived in Gubbio in the second half of the 15th century. Undoubtedly, the foremost figure in this important moment in the history of art was Mastro Giorgio Andreoli whose workshop began producing lustreware as early as the 1480s and would continue to dominate its production in Gubbio and in the Dukedom of Urbino for more than half a century. It became particularly well-known for its production of historiated maiolica featuring the depiction of mythological, religious, allegorical or historical scenes on such typical objects as serving dishes, small concave plates, large dishes and bowls. This kind of precious household pottery was often presented as a decorative wedding gift to put on show as proof of one’s social status. The examples of lustreware by Mastro Giorgio are, without doubt, the most important items on display in the Ceramics Section of the Civic Museum in Palazzo deiConsoli. Among the historiated exhibits, worthy of note, is the small plate featuring “The Fall of Phaeton” and the serving dish depicting “Picus, Circe and Canens”. After 1530, in its final period of activity, the Andreoli workshop was under the direction of Mastro Giorgio’s son, Vincenzo, and specialised, almost exclusively, in what is considered the mass production of a characteristic type of dish on a low foot decorated in relief called “coppaabborchiata” (relief moulded bowl). The usual type of decoration featured in the centre of this kind of dish consisted of coats-of-arms, emblems and images of saints, while the brim was ornamented by a circular array of pine cones, flowers or tongues of fire.