Mari died on 19 October at Milan's San Raffaele hospital, where he was hospitalised. His wife, Italian curator and art writer Lea Vergine, died the following day aged 82.
Throughout his career, he promoted the idea of creating well-designed items for ordinary people.
"One of the most gifted, original and uncompromising designers of our time"
Stefano Boeri, president of Triennale Milano where a major retrospective of Mari's work is currently being held, led the tributes to the designer.
"Ciao Enzo. Te ne vai da Gigante," wrote Boeri on his Facebook page, which translates into English as: "Bye Enzo. You're leaving like a Giant."
"Addio e grazie to one of the most gifted, original and uncompromising designers and design activists of our time," said design writer Alice Rawsthorn on Twitter.
"Goodbye Enzo – pioneer, visionary and speaker of truth to power," wrote Joseph Grima, creative director of Design Academy Eindhoven, on Insatgram.
Born in the Italian city of Novara in 1932, Mari studied at the Accademia di Belle Arti di Brera in Milan from 1952-1956.
Mari was a prolific furniture and product designer
His early works include a series of collaborations with the then recently established Italian brand Danese, which saw the designer create vases, a pencil holder, a series of calendars and his 16 Animals children's puzzle.
Mari also designed the Putrella tray from a slightly bent industrial beam for Danese.
Throughout the 1960s and 70s, Mari designed numerous pieces of furniture for Italian brands. These include the Delfina chair, which was designed for Driade in 1974 and won the Italian Compasso d'Oro industrial design award in 1979.
Among his other noted designs are the Elisa chair and Box chair for Driade and the Tonietta chair for Zanotta.
Alongside product and furniture design, Mari wrote numerous and varied books. In the 1960s he published a book of paintings called The Apple and the Butterfly book, which told the story of a caterpillar.
In the 1970s, he published a guide to making your own furniture from boards and nails called Autoprogettazione.
Retrospective "a fitting tribute to a towering figure"
Mari's varied and extensive work is the subject of a major exhibition curated by Hans Ulrich Obrist and Francesca Giacomelli at the Triennale Milano, which features around 250 of his designs.
"During his lifetime he created an array of extraordinary works – made from paper, wood, glass, pottery, iron, and steel – that move freely between the spheres of art, design, architecture and graphic design, and are now in collections, museums, and homes all over the world," wrote Boeri in the exhibition's catalogue.
"The profoundness of his work along with his deep exploration of the substance of the world act as a counterpoint to his irony and scorn for the superficial mediocrity that he discerns in the fields of design and criticism – with a few rare exceptions such as Ettore Sottsass, who was so far yet so close to him in terms of work ethics."
Mari's archive will be donated to the city of Milan. However, the designer set a condition of his donation that it should not be shown for 40 years, meaning that the current retrospective may be the last time to view some of the objects.
"It is hardly surprising, therefore, that in a recent interview, Mari expressed his firm intention to donate his entire collection of works to the City of Milan, on condition that no one would be given access to his archives for at least forty years," explained Boeri in the exhibition's catalogue.
"He justifies this by claiming that, according to his most optimistic forecasts, it will take forty years before a new generation that is not 'spoiled like today's generation' would be able to make informed use of it, taking back control of the profound meaning of things," he continued.
"The huge retrospective dedicated to Enzo Mari by the Triennale is both a fitting tribute to a towering figure in Italian and international art culture and a shared outcome resulting from his explicit request – given that this was the last occasion to access his archive before this long, self-imposed oblivion."
The main portrait is by Ramak Fazel.
Enzo Mari curated by Hans Ulrich Obrist with Francesca Giacomelli is on view at Triennale Milano in Milan from 17 October 2020 to 18 April 2021. See Dezeen Events Guide for an up-to-date list of architecture and design events taking place around the world.