Venetian glass is still famous hundreds of years after the renaissance. How were these famous glass making shops of Murano organized and controlled?

by knuckles523

I'm sure one or more guilds were involved how were the guilds organized and run?
Were there lots of small shops operating with one master and an apprentice or two, or were the shops larger with a single entity employing masters and other workers?
How was quality controlled and how was the "brand" of Venetian or Murano glass protected, if such a thing existed?
Finally, how were the techniques for making such high quality glass kept a secret for so long? Who controlled how and to whom that information was passed on to?

EDIT:

Thank you to /u/AlviseFalier for guiding me to the name of the Venetian law which regulated glassmaking.

For any one else interested in the Venetian glass industry, using the term Capitolare di Fiolariis, I was able to find some more information.

Venice: Its Individual Growth from the Earliest Beginnings to the Fall of the Republic by Pompeo Molmenti has some good information, but it is pretty old. By old, I mean 110 years; it was published in 1906.

I also found a pretty good summary buried in a review of the work of modern glassblower Dale Chihuly titled Chihuly Over Venice: Dale Chihuly’s Shining Legacy which was written by Tina Oldknow, who is Curator of Modern Glass at the Corning Museum of Glass in Corning, New York.

Since what spurred this interest was watching videos on The Corning Museum of Glass' Youtube channel, they probably deserve a shout out as well. They have some great studio demonstrations and full process videos for anyone else who likes watching artists work.

Thanks to archeology, the Glass-working industry in Venice is dated with certainty to at least the eight century, and is probably older. The first documented presence of a glassmaker appears in a will dated 982 AD, which has as a witness "Domenico, the Glassmaker."

By at least 1224 there was a Glassmaking guild in Venice, but we don't know anything about it until the Venetian government issued a decree in 1271 called Capitolare di Fiolariis heavily regulating the industry. The decree set the start and end time of the work day, the proportion of exports to imports, the length of apprenticeships, and barred Venetian-trained glassmakers from moving abroad (the penalty, ironically enough, was banishment). The paroni de fornaxa, or owners of furnaces, had to answer to a government-appointed Gastald before doing pretty much anything, including hiring an apprentice and moving or enlarging a workshop. I'm sure you can find all forty-six articles of the decree somewhere on-line, although a quick search didn't turn anything up for me.

Glass-working was a double-edged sword for the Republic of Venice: it was a very profitable industry, but a very risky one necessitating furnaces which, if misused, could start dangerous fires. In 1291 the Venetian government passed a decree banning glassmaking on the Rialtine Islands, leading glassmakers to move to the nearby island of Murano.

Calling Venetian glassmaking "regulated" is an understatement. Even the kind of wood (Alder) burned in the furnaces was controlled! In 1315, a law was passed establishing that glassmakers had to use furnaces qui habet tres bocas on three levels, and although other details of glassmaking are lost on me, I can say modern Murano glassmaking does largely use the same techniques.

Glassmakers could become very rich, and on the occasion of the marriage of a glassmaker's daughter to a nobleman in 1376 the government expressly ruled that such a union did not bar the transmission of the title of nobility to the couple's children. The Republic had every incentive to keep glassmakers happy, as their departure was a serious problem. For example, in 1450 one Angelo Barovier became a sort of celebrity for his particularly pure glass, and had very lucrative offers to move abroad from the courts of Milan and Florence. The Barovier workshop remained in Venice and is still there to this day, but the Republic by no means was able to hold onto its exclusive monopoly, if not through the quality of its artisans glasswork.