Born in Genoa on 5 November 1940, he lives in Turin.
Since he first participated in a group exhibition in 1961 and his first solo show in 1964, he has held countless exhibitions at galleries and museums worldwide.
The major retrospectives include Palazzo della Pilotta in Parma (1976), the Stedelijk Museum in Amsterdam (1980), the Nouveau Musée in Villeurbanne (1984), the Staatsgalerie in Stuttgart (1986), the Galleria Nazionale d'Arte Moderna in Rome (1988), the Neue Galerie am Landesmuseum Joanneum in Graz (1998), the Fondazione Prada in Milan (2003), the Kunstmuseum in Winterthur (2005) and the Whitechapel Gallery in London (2014).
He has taken part in a number of Arte povera exhibitions, and on several occasions has shown his work at Documenta in Kassel (1972, 1977, 1982, 1992), and at the Venice Biennale (1970, 1976, 1978, 1980, 1984, 1986, 1993, 1995, 1997, 2013).
His work is represented in many international public collections.
Trained as a graphic designer he has always had a special interest in the printed page. His artistic research has long been coupled with written statements and reflections collected in artist's books:
from Idem, published in 1975 by Einaudi (Turin) with a foreword by Italo Calvino, to Quattro passi.
Nel museo senza muse, brought out in 2006 by the same publisher, and L'autore che credeva di esistere, published by Johan & Levi (Milan) in 2012.
Since 1969 he has also designed sets and costumes for the theatre, notably projects devised with Carlo Quartucci in the eighties and the recent sets for two Wagner operas directed by Federico Tiezzi (2005, 2007).