[5][6] In Paris, he was introduced to the painters Riopelle, Georges Mathieu and Sam Francis as well as visiting museums in Italy, Holland and Spain.
[6] On his return to Montreal in 1953, he was committed to non-figurative art, influenced by French impressionism and American abstract expressionism.
[4] That same year, he became a member of the newly formed multi-faceted Non-Figurative Artists' Association of Montreal, and in 1960, he was elected its last president.
[8][5] In the works of his maturity, McEwen employed an allover field composition bisected by a central vertical but varied colour and ways of handling pigment, either brushed on or applied with a palette knife for a rich impasto surface effect.
In 1963, he showed his work in New York at the Martha Jackson Gallery and after that, in many places abroad, notably Brazil and England.