Penguin Books in Series

I won't attempt to add to the reams and reams already been written about the design of Penguin Books, from the systematic approach defined by Jan Tischold during his brief stint in charge of typography and production, to the distinctive design of books in a particular series, such as these examples of popular fiction, science, crime, and science-fiction from the 1950s to the early 1970s. Its the consistency of the design within each series that appeals to me as much as the styles involved. For example the restricted green and black colour palet and simple-but-striking, Saul Bass-like illustration of the crime series. There are numerous archives of Penguin covers online, but particularly worth a look are the Pelican Project by Things Magazine, which organises the covers by decade, and Joe Kral's personal collection.