Penguin paperbacks date back to 1935, but really reached their height of popularity in the 50s and 60s.
Under the guidance of Germano Facetti, Penguin produced book covers based on common typography and design. Genres were indicated by the colour on the sleeve: Orange for fiction, green for thrillers, light blue for factual and dark blue for biography.
Pelicans and Puffins both followed.
