Castelli was one of the first women ever to obtain a degree in architecture from the Polytechnic Institute of Milan, in 1943. A force behind post-war Italian modern design, in 1949 she founded, together with her chemist and engineer husband, Guilio Castelli, the firm Kartell. It became an institution of reference in the world of design, and the use of plastic became the distinctive emblem of the company and of the Castelli’s creations.The 1972 exhibition at the MoMA, entitled Italy: The New Domestic Landscape, featured diverse products made by the designer; but it was the famous Componobili, a stackable plastic receptacle available in either round or square, that was a runaway success. The Kartell building is the most representative of her work as an architect. Made up of bright red blocks and designed together with Ignazio Gardella, since 1999 this building has housed a museum containing all of the company’s projects, a collection that experienced continual enrichment under the perspicacious gaze of Castelli, with works from international designers such as Philip Starck, Ron Arad and Patricia Urquiola.