Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A pin-up girl, also known as a pin-up model, is a model whose mass-produced pictures see wide appeal as popular culture. Pin-ups are intended for informal display. Pin-up girls may be glamor models, fashion models, and actresses. The term pin-up may also refer to drawings, paintings, and other illustrations done in emulation of these photos (see the list of pinup artists). The term was first attested to in English in 1941; however, the practice is documented back at least to the 1890s. The pin-up images could be cut out of magazines or newspapers, or be from postcard or chromo-lithographs, and so on. Such photos often appear on calendars, which are meant to be pinned up anyway. Later, posters of pin-up girls were mass-produced. They became an instant hit.