Jack Bush was a Canadian abstract expressionist painter, born in Toronto, Ontario in 1909. He was a member of Painters Eleven, the group founded by William Ronald in 1954 to promote abstract painting in Canada, and was soon encouraged in his art by the American art critic Clement Greenberg. With encouragement from Greenberg, Bush became closely tied to two movements that grew out of the efforts of the abstract expressionists: Color Field Painting and Lyrical Abstraction. His painting "Big A" is an example of his color field paintings of the late 1960s.