A pin-up model (known as a pin-up girl for a female and less commonly male pin-up for a male) is a model whose mass-produced pictures see wide appeal as popular culture. Pin-ups are intended for informal display, i.e. meant to be "pinned-up" on a wall. Pin-up models may be glamour models, fashion models, or actors. These pictures are also sometimes known as cheesecake photos.[a] Cheesecake was an American slang word, that was considered a publicly acceptable term for seminude women because pin-up was considered taboo in the early twentieth century.[1]

The classic style of the pin-up originates back from the 1940s. Due to the shortages of materials during WWII, this period of makeup is considered the "natural beauty" look.[20] The US was immersed in war-time economy, which put distribution restrictions on consumer goods.[21] General rationing was supported; women applied mild amounts of products. Despite the rations, "Women were encouraged to keep buying lipstick and to send letters to the front covered in 'lipstick kisses' to boost the morale of the soldiers."