Giancarlo Piretti, born in Bologna in 1940, studied at the Instituto Statale d' Arte in his hometown. He later worked as an interior designer for Anonima Castelli and designed home furniture series, office furnishing systems and the legendary award-winning Plia chair. During his twelve years with castelli, he developed countless innovative furniture designs primarily in the field of seating.

From the late 1970s, he worked with Emilio Ambasz on award-winning designs including two series of ergonomic seating systems, Vertebra und Dorsal.

He introduced his Piretti Collection in 1988 at NeoCon in Chicago, a series with over 50 different office chairs and seating ensembles. The special thing about them was that the furniture had a patented mechanism on the backrest that allows the chairs to be adjusted to the weight of the user. This collection also won many prizes including the IBD (USA, 1989), the ASID (USA, 1990), the Compasso d'Oro (Italy, 1991) and the G-Mark (Japan, 1992).

The legendary Plia chair belongs to the castelli brand, a design institution that has been a member of the Haworth Group since 1992.