Osvaldo Borsani was born in 1911 in Varedo, Italy. He studied Fine Arts at the Brera Academy and Architecture at the Polytechnic University of Milan, where he graduated in 1936. During his studies, Borsani participated in the fifth edition of the Triennale with his project Casa Minima, which earned him a silver medal. He soon began assisting his father Gaetano with the family business, Atelier Varedo, designing and producing furniture influenced by European Art Deco, and opened his first store in Milan. During this period, Borsani started collaborating with Milanese artists such as Lucio Fontana, Agenore Fabbri, Arnaldo Pomodoro, and Gio Pomodoro.

In 1970, Borsani introduced the Tecno Design Center, together with Marco Fantoni and his daughter Valeria, an innovative design laboratory known for its technological and scientific approach to furniture production. Some of the notable designs created by the company include the D70 series.

Borsani passed away on April 16, 1985, in Milan.