Thet were born in Milan in the 1930s. They have been partners in designing architecture, objects, installations and furnishings, as well as town planning, since 1966. During the 1960s they focused especially on temporary furniture and buildings featuring avant-garde signs, materials and industrial technologies. They designed and built several inflatable houses for the Italian Pavilion at the Osaka World Expo and the 14th Milan Triennale.

In 1972 they took part in the exhibit "Italy: The New Domestic Landscape" at New York's M.o.M.A.  At the same time, through a host of installations they tested “borderline” creations standing between architecture and design, including installations for the exhibit "Italienische Möbel Design 1950/80" in Cologne.

In 1979 they received the Compasso d'Oro award. Their works are owned by the major museums worldwide. Their production is portrayed in histories of Italian design and in the main international publications of this field. Besides the design activity they also made a theoretical contribution through the Industrial Design Association. They started their collaboration with Zanotta in 1966. Mr. De Pas died in 1991.