The large slabs delivered from the furnace are cut into strips and then into smaller pieces using only hand-operated shears. When talking about smalti a distinction must be made between “smalti” and “smalti piastrina”: the former are sheared and cut perpendicularly, while the latter are cut in bands with the blade directly on the glass slab, to create relatively regular rectangles.
The tiles essentially have two thicknesses: true smalti are about 1 cm thick while smalti piastrina are about 4 mm thick.
The tesserae cut with the shears, which are rectangular in shape, are intriguing due to the irregularity, the “movement”, the fact that they are cut perpendicularly to the slab, 1 cm thick; their outer “face”, which will form the surface of the mosaic pattern, is in actual fact the inner cut side of the slab, of which the tesserae retain and bring to light the countless variations and nuances of the mixture. Each tessera is unique and cannot be replicated. The luminosity, cut, dimension and uniformity of the paste of each tessera differ.
The smalti produced in this way are particularly suitable to be used for artistic mosaic.
The smalto piastrina is more regular and has a smooth and even surface; in this case it is the top surface of the slab which is used as the “visible” part.