Gear was born in Methil, Fife, and attended Edinburgh College of Art. In 1937 he studied briefly under Fernand Léger in Paris. After the war Gear worked in Germany, mounting exhibitions for the Allies. From 1948 to 1950 he lived in Paris, where he became affiliated to the COBRA movement. The COBRA artists (the initials stand for Copenhagen, Brussels and Amsterdam, the home cities of many of the group's members), advocated a gestural, near abstract style of painting, influenced by primitivism and the art of children.