A book of mosses / Paul Richards. Harmondsworth: Penguin, 1950 (King Penguin Book)

“Tschichold had the daunting task of sistematically organizing the efforts of manufacturers taking part in the evolution of each title. Often several different firms handled the various aspects of book production: binding, letterpress, photo-litho, and paper (...) Often, the production process of each title in the King Penguin series was distributed to several factories throughout England. As the designer, Tschichold had to systematically coordinate and educate each factory's efforts at producing a King Penguin book. Tschichold also began to apply the 'Penguin Composition Rules' as well as the newly established 'King Penguin Standard Grid'. In addition to these design standards, Tschichold replaced the original dull grey paper to a warmer cream color for all of the Penguin series.”

Richard B. Doubleday. Jan Tschichold designer: the Penguin years. New Castle: Oak Knoll; Aldershot: Lund Humphries, 2006 (p. 61, 65)