The formelle in glass strained on slab second produced to the ancient traditions in the Muranesi shops contraddistinguono line BUTTERFLY. They introduce like slabs thickness hard (approximately 12 milimeter) in the following dimensions: 31x31, 39,5x39,5, 48x48, 65x31. According to necessity they come cut on measure. The formelle they come approached directly on the other forming strisce vertical. Between formella and formella they can be inserted batons (always of glass of Wall) of the 12 diameter of milimeter