The industry of Murano glass making, rooted on the island since ancient times, was consolidated in 1295, when the Republic of Venice decreed that every glassmaker of the city, active since the year 1000, had to be transferred to a single area, in order to limit the damage caused by the fires that often flared from the furnaces.
The concentration of the glass artisans in Murano allowed the Venetian government to control their activity, preventing the secrets from being exported abroad. The glassmakers were in fact forced to live on the island, and they need special permits to be able to leave the city of Venice.
A major crisis occurred on the glassmaking island during the fifteenth century, when the manufacture of Bohemian crystal began, inspired by Murano Glass. The crisis ended only when the Venice glass industry began to use such glass for the creation of Murano glass chandeliers, still among the best-known artefacts.
Murano Glass is made from a glass master, assisted by two aides called the servente (servant) and serventino (junior servant).
Murano glass is realized by the Master glassmaker together with some helpers, whose names in order of importance are “servente”, “serventino”, “garzone”, “garzonetto” and “forcellante”; the latter picks up all the glass pieces that have just been processed and puts them into the tempra’s oven. This is the whole workgroup that operates in a Muranese furnace, and it’s called with the slang term “piazza” (square).
There are several processing techniques that can be involved into the production of Murano glass:
- “Rigato Diritto”, which is usually done with a particual type of pliers or scissors;
- ”Rigato Ritorto”, a type of processing that creates a sort of pattern on the glass – “Ballotton”
which is easily recognizable because it produces air bubbles inside the glass.
Murano glass is processed into specific ovens which are made of refractory stone, at a temperature of 1100-1200 °C. Once a piece of glass is completed, it goes through the next stage of tempra. Tempra consists of putting the glass into a particular oven which temperature is kept under control: it remains here all night long, starting from a temperature of 600 °C to get to room temperature the next morning. This process is essential to assure that the various pieces don’t blow up or crack.
The glass’ coloring is obtained by secret (and not secret) formulas that the Master glassmakers have been passing on from father to son for generations. For example, blue glass is obtained by starting from a crystal colored base to which is added cobalt; green color is obtained by adding a larger or smaller quantity of black copper, depending on how intense the green we want must be.
The most refined and expensive color is ruby, because its starting base is not crystal but 24k golden glass. To realize this fascinating coloring, we must add nitric and muriatic acid, then let this compound react: once the chemical reaction is completed, the master creates ruby glass by adding a secret element that only he knows.
Watch the video below to find out how we work in our furnace…