One of the most popular early pin-up girls was Betty Grable, a poster of whom was ubiquitous in the lockers of GIs during World War II.
Many "pin ups" were photographs of celebrities who were considered sex symbols. Others were artwork, often depicting idealized versions of what some thought particularly a beautiful or attractive woman should look like.
An early example of the latter type was the Gibson girl, drawn by Charles Dana Gibson. The genre also gave rise to several well-known artists specializing in the field, including Alberto Vargas and George Petty, and numerous lesser artists such as Art Frahm.