Traitor's purse / Margery Allingham. Harmondsworth: Penguin, 1950
“Jan Tschichold’s reforms dis not involve a radical new look but rather a subtle facelift of all aspects of the cover designs, from the size, weight and position of each element of the typography to the drawing of the logo. The most obvious change was the substitution of Gill Sans for Bodoni Ultra Bold in the publisher’s name. Less noticeable to many, perhaps, was the care taken in optically letterspacing all text set in capital letters, both on the covers and inside the books”.
Phil Baines. Penguin by design: a cover story, 1935-2005. London: Penguin Books, 2005 (p. 57)