Robert Indiana kept a series of illustrated journals during the late 1950s and 1960s, in which he discusses the development of his work as well as his daily life on Coenties Slip.

In his journal entry for December 29, 1962, Indiana records continuing to work on one set of four diamond polygons, and starting another set, varying both in color and size. The page includes sketches of two of the panels from one set, and all four panels of the second set. These works would become Small Black Diamond Polychrome Numeral Quartet Summing Thirty and Four Numbers Summing 30.

Indiana also writes that he painted the front door of 25 Coenties Slip, and that shortly after he finished it began to rain, that "all was drab" and the rest of the day "cold and nasty." He records staying in "all miserable day long," and a "miserable call from Ann Steinbroker [sic] [artist Ann Steinbrocker]."