Born in 1918, Achille and his brothers, Pier Giacomo and Livio, were all trained as architects. Achille’s philosophy was that as a designer you should be a problem-solver, dealing with issues that the consumer might not even realise are there.

A spokesman for the Design Museum said: “He maintained that in order to design a new product, or improve an existing one, you should first decide if it was necessary before looking at what technology and materials were available for doing do.

“He described this process as ‘start from scratch, stick to common sense, know your goals and means’.”

In an interview with the Design Museum, Paola Antonelli, design curator at the Museum of Modern Art, New York, and an architecture student in Milan in the 1980s, said that Achille was one of the most popular tutors. “For his lectures he would arrive with a large black bag, from which he would extract and line up on the table that day’s chosen pieces from his collection of found objects – toys made from beer cans, odd eyeglasses… wooden stools. These were the most effective tools of design instruction,” she said.

Just as the Arco worked as an overhead lamp throwing light some eight feet away from its base, so his famous Sella stool – a bicycle seat on a round base – was, he said, for “when I use the phone. I like to move around but I would also like to sit, but not completely.” His products were humorous and practical. The hole in the base of the Arco is not a design feature, it’s for sliding a broom handle through so that two people can carry it.

During his prolific career, he worked with Flos lighting, Zanotta furniture and Alessi, taking care always to infuse his work with wit. Before his death in 2002, he lamented the “professional disease of taking everything too seriously” and said that one of his secrets was to joke all the time.”