Making the bowl begins with making canes. A clear gather of glass is lowered into a pot of opaque white glass. This is gathered over, yet again, with clear glass. There is a core of clear glass, a thin layer of opaque white glass, and a thin layer of clear. The tip is cooled in water and attached to a post, and this is drawn to a length of 20 or 30 feet. The final diameter of the cane will
be about eight millimeters. This is how a plain cane is made. The compound cane is made by cutting the plain cane into sections and rolling over and picking some
of them up with a mass of clear glass. The canes are reheated. Marvering is used to press the cane into the gather of clear glass. This is attached to a post, pulled, and twisted. The second type of compound cane is made by picking up groups of four canes on the sides of a mass of clear glass, reheating and marvering to make the mass perfectly round and perfectly smooth, and this is pulled and twisted. The canes are cut into lengths of about six inches. The foot is made from about 60 canes. These canes are placed on a ceramic plate, heated, and fused. They’re going to be picked up on a
post on the end of a blowpipe This is a gather of glass. The end has been opened by blowing, and this will be made the correct diameter to allow the fused canes to be rolled up. The gap is closed. The foot is thinly lined with the bubble of clear glass. This is called the sbruffo process. The cane roll-up is divided in two. This will allow the making of two feet. The vessel body is decorated with three types canes in two orientations. They’re placed on a ceramic plate and preheated. Meanwhile, a bubble is blown on the end of a blowpipe and made cylindrical. This is made just the right length and the correct diameter for the roll-up that is about to take place. The canes have been heated to the point of softness, and they are rolled up on the bubble. Pairs of canes are pincered together to form a diamond pattern. This is sometimes called nipt-diamond-waies in 18th-century English
sources. The glass is reheated, the excess trimmed from the bottom, the canes straightened occasionally, and blowing begins. The tip is marvered to keep the glass from blowing thin. Air is blown on the bottom of the bubble to keep it thick. Tooling and blowing creates a spherical shape, and a constriction is formed between the bubble and blowpipe. The sphere is given the shape of an oblate spheroid. Blowing and tooling continues. A mass of glass is added to the tip, and this will become a disk on which the foot will sit. The foot bubble has been reheated. It’s attached to the bottom of
the disk and blown and elongated. It’s cut free of its gathering blowpipe, and a constriction is formed near the end. This constriction will create a hole when the excess glass is broken free. There’s a thick, clear wrap at the edge of the foot. This is flattened to become a band. And after reheating, the soffietta is used to begin inflating the foot further. Combination of reheating and tooling with the jacks is used to give the foot its final profile. The punty (or pontil) is added. It’s attached to the bottom, and a constriction near the blowpipe used to break the vessel free. The opening is reheated in the furnace, and after softening, the jacks are used to open the hole further. The soffietta is used to further inflate the cup. The vessel has an inner fold that’s created by pushing the edge inward and then dilating the hole. The wood jacks (or parcioffi) are used to create the final shape. They produce less friction and fewer toolmarks than metal jacks. The smaller furnace door is removed to allow the increasing diameter to be accommodated in the furnace, and the final shape is given to the cup. The rim has a slight flare, and this is achieved with centripetal force. The vessel is broken free of the punty, placed in the annealing oven for gradual cooling.