From International Signal Code Alphabet
Medium: Ink on paper with tracing paper overlay and collage Dimensions: Sheet: 8 1/2 x 11 in. (21.6 x 27.9 cm) Credit Line: Collection UCLA Grunwald Center for the Graphic Arts, Hammer Museum. Corita Kent Bequest. Accession No.: 1990.1.1158 Paper/Support: Paper Inscriptions: u.r. handwritten in ink: "22"; u.c. handwritten in ink: "reduce (or rather enlarge) to fit"; l.r. handwritten in ink: "make R fit from top to bottom + touching left side / make R + the small writing red on yellow cross + yellow on red areas"
"Untitled." Corita Kent in the Grunwald Center Collection. Los Angeles: Hammer Museum, 2017. https://hammer.ucla.edu/collections/grunwald-center-collection/corita-kent/art/untitled-preparatory-material-for-r-is-for-rabbit/.