Riccardo Dalisi's Ballerinas are colorful floating figures made up of sheets of polymethylmethacrylate that reinterpret his famous compasses in copper and tin, small anthropomorphic sculptures on the border between art and crafts, fairy tales and poetry. In the 2000s, the well-known Neapolitan architect is confronted with an unusual material for him, plexiglass, and for Plart, in 2011 he created the Ballerinas. On that occasion, Dalisi wrote about plastic: «Plastic carries with it the whole history of materials, it coincides with the history of man and his culture. With fire and beating, metals once became more and more sophisticated in form (hammers, rods, sheets of which tin is a nodal point, a watershed for its malleability and resistance). The research on materials continues inexhaustible, leading to the so-called "plastics": they can be easily manipulated and are a pure product of chemistry, an expression of knowledge of the composition of matter. Nature, with its variety, appears today only as a chapter of a larger universe created by man. Geometry (with fractals etc.), devised by human ingenuity, surpasses and encompasses the universe of geometry in nature. It's the same with the materials ".