This is an ancient glass-making technique to make objects, consisiting of distinct parts joined after heat. Incalmo, in Venetian dialect literally means “graft” as in joining two parts. The name was giving on the first half of the twentieth century by the Venini factory on Murano, in Venice. In simple words two or more elements of different colours fused to create a single piece. The glass artist blows two separate bubbles of glass, opens them and joins them together to form a single bubble. This system requires uncommon technical mastery on the part of the glassblower, but outstandingly beautiful objects have been created, such as those by Thomas Stearns and Tapio Wirkkala for Venini & C. in the early 60s. Aimed at obtaining multiple areas of different colours on the same surface, all the pieces are joined togeteher very accuarately andf finished as desidered. If necessary, the operation can be repeated over and over. Incalmo sculptures could be also achivied by insert a cooler piece (rigid) into a hotter one (softer). They are then joined together very accurately and finished as desired.