It often happens that we find little treasures in our stacks when we're looking for other things. A couple of days ago we spotted the delightful title Flowers in Nature and Design, by Fritzi Brod. Dating from 1947, the folio-sized, 24-page book of stylized plant drawings appears to have been published for use by designers--a sort of clip art library of floral motifs. What is most fascinating about the book is its set of drawings that are accompanied by glassine overlays, which illustrate the color separation process used in multiple-plate color printing. This method, which is employed in creating most commercially printed items, involves the division of an image into cyan, magenta, and yellow (and in contemporary printing, black) layers to allow for, in combination, the creation of all additional colors in the image. Brod's overlays demonstrate this process of division and recombination in a wonderful, hands-on way.