Manzoni made his debut at the 4^th Market Fair at Sforzesco Castle in Soncino, in 1956. The following year, he took part in the exhibition Arte Nucleare at the San Fedele Gallery in Milan: he painted anthropomorphic silhouettes and paintings with imprints of objects. On 5 November, he took part in the “San Fedele Painting Prize 1956” at the San Fedele Gallery in Milan, and a month later, on the 9 December, he published Per la scoperta di una zona di immagini, co-written with Sordini, Camillo Corvi-Mora and Giuseppe Zecca, the first in a full series of posters that would mark the beginnings of his career. He also produced the first Achromes (1957), large white surfaces soaked in glue and kaolin.
In 1958, he exhibited together with Lucio Fontana and Enrico Baj, and his collaboration with Enrico Castellani and Agostino Bonalumi began. The Fontana Baj Manzoni exhibition opened on 4 January at the Galleria Bergamo in Bergamo and moved on to the Galleria del Circolo di Cultura in Bologna on 23 March. The introductory text is by Luciano Anceschi, a great scholar of aesthetics and founder, two years earlier, of the avant-garde magazine Il Verri.

According to Anceschi, in the first edition of the exhibition, Manzoni exhibited “chaotic surfaces with a colour that simulates lacquer or enamels, sharp nightmares of the subconscious, obscure clutches of fantastic and repugnant presences, not without surrealist reminiscences and a dreamlike gnomic style”. While in the second edition he “attempts dazzlingly white surfaces, entrusted to the sensitivity in handling matter and interrupted by plastic reliefs and their shadows”, presenting his new works for the first time.
Achromatic plaster works are also the protagonists of the solo exhibition that opened on 22 April at the Galleria Pater: two of them were purchased by Antonio Boschi, who later donated his collection to the Milanese Civic Art Collections.
A new edition of “Bonalumi Castellani Manzoni” was presented on the 8 September at the Galerie Kasper in Lausanne, which also published the magazine Art actuel international. The birth in Milan of the magazine Azimuth, published by Manzoni and Castellani, based at Manzoni’s home at No. 4 via Cernaia and printed at Antonio Maschera’s printing house at No.14 via Palermo, the same place where many of his early publications were produced and where he carried out his experiments with paper, was officially announced on the 3 September. The gallery, located in a basement at No.12 Via Clerici, was a self-managed space that opened on the 4 December with Manzoni’s solo exhibition Le Linee, introduced by Vincenzo Agnetti.
Manzoni’s style became increasingly radical. He went beyond the surface of the painting and proposed a series of provocative works, intolerant of tradition. These increasingly radical works included Manzoni’s Lines traced on strips of paper, rolled up and stuffed into a cardboard tube (the longest one, created in Herning, Denmark, in 1960, thanks to the patronage of Aage Damgaard, measures 7200 metres); Corpi d’aria (Bodies of Air) and Fiato d’artista (Artist’s Breath – balloons containing Manzoni’s breath); Uova (Eggs), sculptures authenticated by the artist’s fingerprints; Basi magiche (Magic Bases), plinths on which anyone can become a work of art; new Achromes, made from the most varied materials, from fibreglass to plasticised bread rolls, some strictly white, others in phosphorescent colours.
On 21 July 1960, Piero Manzoni presented one of his most famous performances at the Azimut Gallery in Milan: the Consumazione dell’arte dinamica del pubblico divorare l’arte (Consummation of Dynamic Art by the Public Devouring Art). The artist signed some hard-boiled eggs with his thumbprint, which were eaten on the spot by the public. In 1961, at Galleria La Tartaruga in Rome, Piero Manzoni signed human beings for the first time, transforming them into living sculptures. In May the same year, he made Merda d’artista (Artist’s Shit), in a series of ninety pieces, a six-centimetre diameter sealed can, with a printed label bearing the words “Merda d’artista’” in Italian, English, French and German and the following noted on the label: “Contents 30 gr net. Freshly preserved. Produced and tinned in May 1961”, with the price of thirty grams of gold. The work was presented to the public only after several key exhibitions: “Zero Edition Exposition Demonstration” at the Galerie Schmela di Düsseldorf, on the 5 July, with Arman, Aubertin, Pol Bury, Castellani, Fontana, Klein, Lo Savio, Mack, Manzoni, Peeters, Piene, Schoonhoven, Soto, Spoerri, Tinguely, Uecker, “Internationale Malerei 1960-61” at the Deutsch-Ordens-Schloss, Wolframs-Eschenbach, on the 15 July, and “Nove tendencije” at the Galerija Suvremene Umjetnosti of Zagabria, on the 3 August.
In 1962, Manzoni made plans with publisher Jes Petersen to publish a book with blank pages: “Piero Manzoni. The Life and the Works”. In the Achromes of this period, the iterative visual cell consists of actual bread rolls, Milanese “michette” to be precise. In others he uses pebbles, or polystyrene foam beads. White always cover everything to standardise, desensitise and make everything a very present but alienated surface. Others are parcels wrapped in newspaper or packaging paper tied with string and sealed with lead and sealing wax, as if they were postal items, presented in pairs.
In 1963, he was present at the “Mostra monocroma”, Galleria Il Fiore, Florence, 16 January, and on the 25 January he held a solo exhibition at the Galerie Smith in Brussels, where he presented his Achromes with bread rolls applied to the support for the first time.
Piero Manzoni’s works are exhibited in museums all over the world: Tate Modern, London, Moma, New York, Centre Pompidou, Paris, NEUES MUSEUM Staatliches Museum für Kunst und Design Nürnberg, Germany, HEART – Herning Museum of Contemporary Art, Bitten & Aage Damgaards Plads, Denmark, Museo del Novecento, Milan, Galleria Civica d’Arte Moderna, Turin, GNAM, Rome.
Manzoni died suddenly of a heart attack in his studio in Milan on the 6 February 1963.