Opinion Ciatti Ptolomeo free standing bookshelf. The “column of knowledge” by Opinion Ciatti is 215 cm high and is made of sheet steel, in white, with polished stainless steel base. A fabulous way to display books as the thin metal shelving virtually disappears leaving the impression the books are simply stacked and floating. Space saving and stylish way to house your collection. Bruno Rainaldi received the “Compasso d’Oro 2004” for his design of the Ptolomeo collection. The “invisible” bookshelf by Opinion Ciatti has been often copied, but the original is unmatched in quality and manufacture. Comes with a set of 7 shelf extenders. Recommended retail prices $2,125 plus extensions $295 for set of 5.