The idea of openly marking the values and suits on the backs of cards is frequently misattributed to Ted Lesley, because of the popularity of the Lesley Marked Deck which used white press-on lettering on the backs of the cards. However, Page Wright suggested using a typewriter on a blue-backed deck to do the same job. This is mentioned by Fred Braue in the Hugard's Magic Monthly, Vol. 5 No. 6, Nov. 1947, p. 370. Braue begins the note with “Out of the Past,” which may suggest Wright published this idea somewhere earlier. Wright died in 1930, so the idea most likely goes back to the 1920s.
Much better known was Al Baker's open marking system, published in Pet Secrets, 1951, pp. 54-6. Baker altered the design of Angel-backed cards to create large white numbers and letters that are easily read but are not obvious to those who unaware of the idea.