“Be on Time” Progressive Proof Lithographed Booklet. Detroit, Calvert Lithographing Co., ca. 1910. David C. Cook Publishing Co., Elgin, Illinois. A set of four different “Be on Time” cards in a progressive proof booklet from Calvert’s archives. Five pages total, of which four have an impression of a different color used in the final fifth page, which shows the final product before cutting. Each card. Pages measure 10 x 7 ½.” Some soiling from use. Good.