"Sommerso”, which in Italian literally means “submerged” is a technique used to create several layers of glass (usually with different contrasting colors) inside a single object, giving the illusion of “immersed” colors that lay on top of each other without mixing. This is done by uniting different layers of glass through heat and repeatedly immersing them in pots of molten colored glass. This technique is quite recognizable: it is characterized by an outer layer of colorless glass and thick layers of colored glass inside it, as if a big drop of color had been captured inside the transparent glass. When one first sees these objects, it seems almost impossible to conceive such beautiful colors being locked so perfectly inside what would seem solid glass, and then undoubtedly one begins to wonder how ever did they manage to achieve such a complex game of shapes and colors right in the middle of a clear glass object.
Antonio Da Ross, a highly skilled Venetian glassmaker, first developed the sommerso technique in Murano in the late 1930’s. His works suddenly became famous thanks to the effect of contrasting sunken colors inside one single piece, and were soon recognized by the Venice Biennale and many other museums across the world. Paolo Venini, another famous glassmaker, perfected the technique around the same time, but it was Seguso d’Arte who made it world famous during the 1950’s. Thanks to Flavio Poli (Seguso’s artistic director from 1937 to 1963), the Seguso house discovered many variations of this technique, which included the addition of gold leaf, minerals, or bubble glass, all of which gave his pieces an iridescent golden effect. Most of his pieces seem to be corroded by some kind of acid or mineral, yet the subtle difference of transparency and layers can still be seen thanks to the sommerso technique. The “Bullicante” glass, sometimes considered a different technique, can be considered as a variation of the sommerso technique. It consists of overlaying glass bubbles inside the main object, thus giving the illusion of small air bubbles trapped inside the artwork.