Charles Gross painted action oriiented covers for pulp magazines anf their offspring , paperbacks, for almost 50 years beginning in the late 1930s. He painted hundreds of freelance pulp covers for Action Stories, Air Stories,Baseball Stories, Complete Northwest, Detective Book Magazine, Fight Stories, Football Stories, Jungle Stories, North West Romances, and Wings. He also sold pulp covers to A. A. Wyn's Periodical House, for titles such as Ace Sports and Western Aces.
He was born in Brooklyn in 1909, of Hungarian immigrant parents. His father was a successful freelance artist who did work for Montgomery Ward's catalogs.
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Striking cover for THE AVENGER # 74 paperback, 1970s
Early work, 1938
Sc Fi from 1945
Another Avenger cover
These 2 look like they are from Don Pendelton's The Executioner paperback series.