Thijn was born in Emmen in 1933. He worked as a professor of radiology. Thijn was a painter since 1966. In his first works the medical world can still seen. Later he focused on other subjects that play a role in society. He also painted portraits and still lifes. His latest works are more about life. Thijn describes himself as "a symbolic-surrealist painter". He was a member of "Het Drents Schildersgenootschap" (since 1974).