In the 16th century, the filigrana technique was closely guarded by the artisans of Murano. The Venetians used glass as a form of currency, and the highly skilled process behind the spiralling filigree stripes gave it even higher value. Today, the old wood-burning furnaces have been replaced with gas equivalents and production is no longer limited to Murano, but many of the same traditions – and some of the same air of secrecy – still exist. Here, photographer Matteo Cuzzola reveals a rare moment behind the scenes at the glass workshop in Treviso that creates the Filigrana Light for Established & Sons.

The ovens operate 24 hours a day, seven days a week. The days are dedicated to blowing glass, and at night, there is a shift where people prepare the raw glass for the following day. I arrived at 7am. It was a very cold day with snow out-side, but when I entered it was like being in California – about 25 degrees and people were wearing shorts and T-shirts, working near the big ovens.

There are only a small number of Maestri Vetrai, or glass masters, in Italy. The man in the red T-shirt in my photo-graphs is a glass master, and he handles the piece of glass just in the final, most important part of the making, rotating the glass continuously while he blows it to create the final shape.

The atmosphere was quiet. They are very calm because everyone knows what to do and everyone has a particular role. For example, there is an expert who only works with the small pieces they add to create the Filigrana. It’s a very slow process, and every piece they create is unique in some way.

They are not used to having strangers in the workshop. No one is comfortable having their photograph taken by a stranger while they work, you have to talk to them and be-come, not exactly friends, but more familiar. But there is an-other reason that they are a little bit guarded with strangers. This is an old art we have in Italy, and every day someone tries to steal this unique technique. They don’t want other people to learn the secret. So I feel very privileged to have been allowed in.