Earning international acclaim, his work has been interpreted as Surrealism, a sandbox for the subconscious mind, a re-creation of the childlike, and a manifestation of Catalan pride. In numerous interviews dating from the 1930s onwards, Miró expressed contempt for conventional painting methods as a way of supporting bourgeoise society, and famously declared an "assassination of painting" in favor of upsetting the visual elements of established painting.
In 1959, André Breton asked Miró to represent Spain in The Homage to Surrealism exhibition together with works by Enrique Tábara, Salvador Dalí, and Eugenio Granell. Miró created a series of sculptures and ceramics for the garden of the Maeght Foundation in Saint-Paul-en-Forêt, France, which was completed in 1964.
Miró's oft-quoted interest in the assassination of painting is derived from a dislike of bourgeoise art of any kind, used as a way to promote propaganda and cultural identity among the wealthy. Specifically, Miró responded to Cubism in this way, which by the time of his quote had become an established art form in France. He is quoted as saying "I will break their guitar," referring to Picasso's paintings, with the intent to attack the popularity and appropriation of Picasso's art by politics.
In an interview with biographer Walter Erben, Miró expressed his dislike for art critics, saying, they "are more concerned with being philosophers than anything else. They form a preconceived opinion, then they look at the work of art. Painting merely serves as a cloak in which to wrap their emaciated philosophical systems."
Four-dimensional painting is a theoretical type of painting Miró proposed in which painting would transcend its two-dimensionality and even the three-dimensionality of sculpture.
In his final decades Miró accelerated his work in different media, producing hundreds of ceramics, including the Wall of the Moon and Wall of the Sun at the UNESCO building in Paris. He also made temporary window paintings (on glass) for an exhibit. In the last years of his life Miró wrote his most radical and least known ideas, exploring the possibilities of gas sculpture and four-dimensional painting.
One of Miró’s most important works in the United States is his only glass mosaic mural, Personnage Oiseaux (Bird Characters), 1972-1978. Especially created for Wichita State University’s Edwin A. Ulrich Museum of Art, Kansas. The mural is one of Miró’s largest two-dimensional projects, undertaken when he was 79 and completed when he was 85 years of age. Fabrication of the mural was actually completed in 1977, but Miró did not consider it finished until the installation was complete.
The glass mosaic was the first for Miró. Although he wanted to do others, time was against him and he was not able. He was to come to the dedication of the mural in 1978, but he fell at his studio in Palma de Mallorca, Spain, and was unable to travel. His island home and studio in Mallorca served him from 1956 until his death in 1983.
The entire south wall of the Ulrich Museum is the foundation for the 28 ft. by 52 ft (8.53 m. x 15.85 m.) mural, comprised of one million pieces of marble and Venetian glass mounted on specially treated wood, attached to the concrete wall on an aluminum grid. A gift of the artist, donor groups paid for the fabrication by Ateliers Loire of Chartres, France, and for its installation. The Ulrich Museum also acquired the 5 ½ ft. by 12 ft. oil on canvas maquette for the mural, but it has since been sold to establish a fund to support the museum’s acquisitions and any repairs needed to the mural. The entire mural was originally assembled by one artisan at Ateliers Loire using Miró’s maquette as a guide.
Fabricated under Miró’s personal direction and completed in 1977, the 40 panels comprising the mural were shipped to WSU, and the mural was installed on the Ulrich Museum’s façade in 1978. Although it has received little recognition, the mural is a seminal work in the artist’s career, being one of Miró’s largest two-dimensional works in North America and the only type of its kind by the artist.
Many of his pieces are exhibited today in the National Gallery of Art in Washington and Fundació Joan Miró in Montjuïc, Barcelona; his body is buried nearby, at the Montjuïc cemetery. Today, Miró's paintings sell for between US$250,000 and US$17 million; the latter was the auction price for the La Caresse des étoiles on May 6, 2008 and is the highest amount paid for one of his works.
Joan Miró won several awards in his lifetime. In 1954 he was given the Venice Biennale print making prize, in 1958 the Guggenheim International Award, and in 1980 he received the Gold Medal of Fine Arts from King Juan Carlos of Spain.
In 1981, Fundació Pilar i Joan Miró a Mallorca is established by the Palma de Mallorca City Council.