George Brown Petty IV was an American pin-up artist. His pin-up art appeared primarily in Esquire and Fawcett Publications's True but was also in calendars marketed by Esquire, True and Ridgid Tool Company. Petty's Esquire gatefolds originated and popularized the magazine device of centerfold spreads. Reproductions of his work, known as "Petty Girls," were widely rendered by military artists as nose art decorating warplanes during the Second World War, including the Memphis Belle.

A pin-up model is a model whose mass-produced pictures and photographs have wide appeal within the popular culture of a society. Pin-up models are usually glamour models, actresses, and fashion models whose pictures are intended for informal, aesthetic display, such as being pinned onto a wall. Beginning in the 1940s, pictures of pin-up girls were also known as cheesecake in the U.S.