Micromosaic was invented in Rome in the second half of 1700s, and it flourished as an artistic handicraft from the late 1700s to the following century.
In the second half of 1500s started a major project for Saint Peter’s Basilica: decorating its vaults with mosaic, and creating mosaics based on the existing paintings, using colored vitreous materials – also known as enamels. The enamels were produced in Venice, but the same production started shortly after in Rome. In that context small micromosaic tiles started to be produced also in the Vatican Mosaic Studio.
The glass was spinned on thin sticks, and then divided into tiny tiles. The base onto which micromosaic was put together could be metallic – a copper foil with raised borders, or a hollow stone foil, or some other material; the tiny tiles were then fixed with a proper adhesive.
The final works were small-sized, made with great precision and finished with the same care; they could be inserted in objects like small tables with a marble top, snuffboxes, paperweights and so on; or, when used for jewellery, they could be applied to brooches and jewels.
(Excerpt taken from Micromosaico: storia, tecnica, arte del mosaico minuto romano, by Chiara Bertaccini and Cesare Fiori, Edizioni del Girasole 2009)