When the animation studio Bradbury worked for after the war folded he turned to comics, drawing humour and adventure strips for Amalgamated Press's Knockout. Work for Valiant (on strips including Mytek the Mighty and The House of Dolmann), Buster (on strips including The Leopard from Lime Street), Jet (on Von Hoffman's Invasion) and Smash! (on Cursitor Doom) followed, and he also drew the one never published issue of IPC's abortive Captain Britain title (unconnected to the later Marvel UK character) in 1973. In 1976 Valiant became part of Battle Picture Weekly, for whom Bradbury drew a number of strips including The Fists of Jimmy Chang and Joe Two Beans, as well as Hook Jaw for Action.
From 1977 to 1993 Bradbury laboured under Tharg the Mighty at 2000 AD, working on series such as Tharg's Future Shocks, Tharg's Time Twisters (he drew the first), Invasion!, Mean Arena and Rogue Trooper, and also drew Doomlord for the revived Eagle. His gritty, realistic style was invaluable in bringing these worlds to life.