Took a correspondence course from the Famous Artists School.
Was mostly self-taught but he did watch TV art instructor Jon Gnagy on Saturday mornings.
Was a big fan of the comic strips of Hal Forster (Prince Valiant) and Alex Raymond (Flash Gordon).
Dropped out of high school in 1966.
Worked at the daily newspaper the Baltimore Sun where he drew editorial cartoons and worked in the production department.
Contributed illustrations and strips to fanzines Squa Tront and Graphic Showcase which published his 8-page comic "Uncle Bill's Barrel" in 1969.
Wrightson's first published story was the Marv Wolfman written "The Man Who Murdered Himself" in House of Mystery #179 in 1969.
His comic cover illustrations included a frightening vampire (House of Mystery #211), an ancient killer tree (House of Mystery #217), ghoulish zombies (House of Secrets #100) and a crazed werewolf (House of Mystery #231).
His artistic influences included Frank Frazetta, Al Williamson, Al Dorne, Graham Ingels, Jack Davis and Howard Pyle.