The History Of Murano Glass

Murano’s reputation as a center for glassmaking was born when the Venetian Republic, fearing fire and destruction to the city’s mostly wood buildings, ordered glassmakers to move their foundries to Murano in 1291. Murano glass is still interwoven with Venetian glass.

Murano's glassmakers were soon the island’s most prominent citizens. By the 14th century, glass makers were allowed to wear swords, enjoyed immunity from prosecution by the Venetian state and found their daughters married into Venice’s most affluent families. Of course there was a catch: Glassmakers weren't allowed to leave the Republic. However, many craftsmen took this risk and set up glass furnaces in surrounding cities and as far afield as England and the Netherlands.

Murano’s glassmakers held a monopoly on quality glassmaking for centuries, developing or refining many technologies including crystalline glass, enameled glass (smalto), glass with threads of gold (aventurine), multicolored glass (millefiori), milk glass (lattimo), and imitation gemstones made of glass. Today, the artisans of Murano are still employing these century-old techniques, crafting everything from contemporary art glass and glass jewelry to murano glass chandeliers and wine stoppers.

Today, Murano is home to the Museo Vetrario or Glass Museum in the Palazzo Giustinian, which holds displays on the history of glassmaking as well as glass samples ranging from Egyptian times through the present day.


The Art of Glassmaking

The process of making Murano glass is rather complex. Most Murano glass art is made using the lampworking technique. The glass is made from silica which becomes liquid at high temperatures. As the glass passes from a liquid to a solid state, there is an interval when the glass is soft before it hardens completely. This is when the glass-master can shape the material.

Orange Murano Beads

The other raw materials, called flux or melting agents, soften at lower temperatures. The more sodium oxide present in the glass, the slower it solidifies. This is important for hand-working because it allows the glassmaker more time to shape the material. The various raw materials that an artisan might add to a glass mixture are sodium (to make the glass surface opaque), nitrate and arsenic (to eliminate bubbles) and coloring or opacifying substances.


Colors, techniques and materials

Colors, techniques and materials vary depending upon the look a glassmaker is trying to achieve. Aquamarine is created through the use of copper and cobalt compounds whereas ruby red uses a gold solution as a coloring agent. The millefiori technique begins with the layering of sliced canes of glass and conterie or tiny glass beads are formed by cutting thin glass canes into sections when cold then rounded when hot. Filigree, incalmo, enamel painted, engraving, gold engraving, lattimo, ribbed glass and submersion are just a few of the other techniques a glassmaker can employ.

 

Tools

It is essential that Murano artisans use tools in the making of their glass. Some of these tools include borselle (tongs or pliers used to hand-form the red-hot glass), canna da soffio (blowing pipe), pontello (an iron rod to which the craftsman attaches the object after blowing in order to add final touches), scagno (the glass-master's work bench) and tagianti (large glass-cutting clippers)

 

Ancient Glass Making

Since ancient times man has paid an almost mystic- attention to glass, attributing something magical and supernatural to this transparent material. Magicians of legend could predict the future by gazing into a crystal sphere, chemists and alchemists studied prisms in search of a stone which would turn metal into gold, magic that was born in flames and like that fire that gave life to the popular belief of the Phoenix, the mythological bird with the golden plumes, glass is synonymous with beauty. Still today, for the visitors who come to Murano, the same scenes which inspired writers and legend are represented. In fact the furnace structures have remained unaltered over time and new technology is seen only in small details. All this is because of the attachment the master glass-blowers have towards tradition. Like a clock, they seem to have stopped time in the more than one thousand years of history of glass-blowing in Venice. The glass masters "battono" (beat, i.e. use) the same glass-blowers pipes and the same instruments which were knowingly forged in the machine shops which were built up over the island which, together with other small activities, has made Murano one of the centers of Venetian commerce. The origins of the art of glass blowing in Venice go back to before the first millennium. This is confirmed by a document written by a Benedict monk, Domenico called "Fiolario", who manufactured phials for use in the home.


There is no certainty as to the shape of this phial since not one, neither whole nor in pieces, survived to the present day. We can only hypothesize as to the aspect of the phial from some iconographic documents. The technique used to make the phial was that of blowing into glass using those instruments that the late Roman glass blowing activities had passed down through the ages. It is presumed that later the technique was refined in Venice more than any where else in Europe because of the trading contacts that the Venetians had with the Orient and above all with countries that already had an ancient tradition in glass blowing such as the Fenici, the Syrians and the Egyptians. Such traditions, renewed in the celebrated furnaces of Islam, were an occasion to reconstruct both Western and Oriental knowledge and techniques there by giving the Venetian production a particularness that made their glass so important throughout the world over the course of centuries. Today Venetian glass production is at its pinnacle, and is world renowned for it's quality and form.


Art of the glass

The specific characteristics of glass is the way in which it solidifies, passing from liquid to solid by increasing the viscosity and passing from the rigid to the to the solid state which is obtained at a temperature of about 500 degrees C. (centigrade). In this interval of time, the so called "workable thermal interval", the Glass Master can give shape to objects, the finished products of which will retain the rigidity of a solid body while maintaining the transparency of liquid. Glass is composed of about 70% sand and silica which is transformed into a liquid state at a temperature of 1700 degrees C. In order to melt the silica at a lower temperature a "fondente" or "flux" which is used as a melting agent is added. This composition is incisive in glass technology not only because of the economic savings but also because it becomes a protagonist in the characteristics of Murano glass for which it is famous through out the world. The primary melting agent is soda, which has the property to lengthen the solidification time thus allowing optimum conditions in which the Glass Master may work the glass. The higher the percentage of soda the slower the glass solidifies ("slow" glass), in any case the presence of a melting agent must not be excessive, in fact there is an equilibrium that must be respected. If this equilibrium is not respected, over a period of time the glass will bring the flux to the surface and the object will become opaque (in "Muranese" terms it is said that the glass " sputa" spits out the soda). In order to limit this tendency a stabilizing agent is used: limestone or calcium carbonate. Other components which are added to the composition are nitrate and arsenic which have a refining action, facilitating the expulsion of air bubbles and making the fusion more homogeneous. If colours or opaque agents are added to the primary ingredients indicated the famous coloured or opal glass is created. Today the pureness of the soda is guaranteed by the Solvay process which gets its name from its inventor, while in ancient times melting agents came from the Orient.


In fact an analysis of ancient glass indicates that plant ash containing a high quantity of potassium oxide and magnesium was used as flux. In the Syriac language these substances are known as "allume di catino" and "cenere di soria". It may be suspected that the decision to use this particular potassium based ash which was sanctioned by a Major Council edict of 1306 which prohibited the use of potassium ash made from processed ferns had a political basis. In fact such an edict ensured that the "Galee" (Venetian ships) of the Venetian patriarch would return from the Orient with their holds filled. The plant ash under went a purification process in order to obtain the "sale di cristallo" or the "sale di vetro" or glass salts, which when used together with pure silica and magnesium from Piemonte was the most precious decolorant used by Angelo Barovier in the XV Century to obtain that most precious of Murano glass: crystal. As far as silica is concerned, from 1300 to the XVIII century stones from the Ticino river were used. The so called "cogoli del Tesin were very pure while the "cogoli de Verona were less precious because as is written an anonymous manuscript from the XVIII C., it makes the glass "zaleto" (yellow). Later excavated silica sand was used and is still used today. The most famous silica is that which extracted in Istria and along the Dalmatian coast which is quoted in documents as sand from Pola and Lisa. The pureness of the glass today is guaranteed, not only because of the quality of the raw materials but also for the manner and ease with which fusion takes place thanks to the use of methane gas as fuel which quickly reaches high temperatures.The most widely used furnace is the "crogioli or slow-baking furnace with a medium capacity of 500 kilograms a day. These slow-baking furnaces are known by the Glass Masters, in order of size, as "palea", "ninfa" and "curisiol". The composition is loaded into an empty slow-baking furnace in two or three stages.


Venetian glass

Venetian glass is a type of glass object made in Venice, Italy, primarily on the island of Murano. It is world-renowned for being colorful, elaborate, and skilfully made. Many of the important characteristics of these objects had been developed by the 13th century. Toward the end of that century, the center of the Venetian glass industry moved to Murano. Byzantine craftsmen played a role in the development of Venetian glass, an art form for which the city is well-known. When Constantinople was sacked by the Fourth Crusade in 1204, some fleeing artisans came to Venice. This happened again when the Ottomans took Constantinople in 1453, supplying Venice with still more glassworkers. By the 16th century, Venetian artisans had gained even greater control over the color and transparency of their glass, and had mastered a variety of decorative techniques. Despite efforts to keep Venetian glassmaking techniques within Venice, they became known elsewhere, and Venetian-style glassware was produced in other Italian cities and other countries of Europe.


Murano is usually described as an island in the Venetian Lagoon, although like Venice itself it is actually an archipelago of islands linked by bridges. It lies about a mile north of Venice and is famous for its glass making, particularly lampworking. Murano was settled by the Romans, then from the sixth century by people from Altino and Oderzo. At first, the island prospered as a fishing port and through production of salt. It was also a centre for trade, through the port it controlled on Sant'Erasmo. From the eleventh century, it began to decline as islanders moved to Dorsoduro. It had a Grand Council, like that of Venice, but from the thirteenth century Murano was ultimately governed by a podesta from Venice. Unlike the other islands in the Lagoon, Murano minted its own coins.


In 1291, all the glassmakers in Venice were forced to move to Murano due to the risk of fires. In the following century, exports began, and the island became famous, initially for glass beads and mirrors. Aventurine glass was invented on the island, and for a while Murano was the main producer of glass in Europe. The island later became known for chandeliers. Although decline set in during the eighteenth century, glassmaking is still the island's main industry. In the fifteenth century, the island became popular as a resort for Venetians, and palaces were built, but this later declined. The countryside of the island was known for its orchards and vegetable gardens until the nineteenth century, when more housing was built.


Lampwork glass beads

Lampworking is glassworking using a torch to melt and shape the glass. It is also known as flameworking or torchworking, as the modern practice no longer uses oil-fueled lamps. Although the art form has been practiced since ancient times, it flowered in Murano, Italy in the 1300s, and spread from there to the rest of Europe. In the 1850's lampwork incorporated into glass domed paperweights, primarily in France, became a popular art form, still collected today. In addition to artwork, lampworking is used to create scientific tools, particularly for chemistry. Early lampworking was done in the flame of an oil lamp, with the artist blowing air into the flame through a pipe. Most artists today use torches that burn either propane or natural gas for the fuel gas, with either air or pure oxygen as the oxidizer.