Penguin already had the tri-band cover when Jan Tschichold arrived in 1947. What it did not have was a law. In two years he redesigned some five hundred titles and wrote four pages — the Penguin Composition Rules — fixing indentation, punctuation, capitals, footnotes and folios for every compositor working on the list.

This system reads as that law made visible. A white centre panel between two colour bands, author and title in a humanist sans, a cartouche above, hairline rules, measured margins, letter-spaces equalised by eye rather than by machine default. Nothing is decorated. Everything is placed.