Bertolio was born in Mornago, Italy, in 1934. He studied weaving in Bergamo, and became very interested in ancient cave paintings in Spain, which influenced his early art. Then he fell under the influence of Gauguin, Kandinsky, Cezanne and finally Mondrian, who was the greatest stimulant and inspiration for his art.
Since 1970 he has lived and worked in Barasso. His work at that time resembled the optical work of Soto and Cruz Diez, but by the 1980s he had moved in the direction of irregular designs, influenced by Mondrian. He also did works that he called “Constructive Symbolism.”
In the 1990s he did more constructivist work. As his work became more like that of the MADI artists, in 1999 he joined the International MADI Movement. He ceased using the square and rectangular frame, and almost all of his work since 2000 has been of irregular shape and three dimensions.