His father, Gaetano Borsani, was a
noted furniture craftsman who won
the silver medal at the Monza Triennale
of 1927, and his twin brother Fulgencio
would be his collaborator and business
partner. In 1937, Osvaldo entered
the Politecnico di Milano to study
architecture. After completing his
degree, he joined the family business,
Atelier Varedo (later Arredamento
Borsani) as a furniture designer.
Throughout the 1940s and early 50s,
Osvaldo produced a large body of work
including case goods, storage pieces
and seating. Especially noteworthy
was a 1946 wall-mounted shelving system.
Among his clients were Crippa, Fabbri,
Fontana and Sussu.
1953, Osvaldo and Fulgencio founded
a firm called Tecno which, as its
name suggests, became known for its
technology- and research-based approach
to furniture design. In 1955, Tenco
issued one of its best-known pieces,
the P40 chaise longue. Described as
a "machine for sitting",
it featured rubber arms and could
assume 486 distinct postures; the
D70, a sofa version, was also manufactured.