He was taught matte painting by British matte painting pioneer
W. Percy Day.
He became head of Universal's Matte Department in 1963.
He moved to the United States in 1954.
His artistic talent led to a promotion at British Gaumont into a job
where he would paint signs and scenery.
His first job in the industry was as an errand boy at Gaumont British
Studios.
In addition to the quality of his work, Whitlock was known for
the speed at which he was able to complete his assignments. All of the
matte paintings for Earthquake (1974) were completed in only
12 weeks.