In preparing these instructions, Gaspard-Michel LeBlond, one of their authors, urges the use of uniform media for registering titles, suggesting that “ catalog materials are not diffi cult to assemble; it is suffi cient to use playing cards [. . .] Whether one writes lengthwise or across the backs of cards, one should pick one way and stick with it to preserve uniformity. ” 110 Presumably LeBlond was familiar with the work of Abb é Rozier fi fteen years earlier; it is unknown whether precisely cut cards had been used before Rozier. The activity of cutting up pages is often mentioned in prior descrip-tions.

Rozier chances upon the labor-saving idea of producing catalogs according to Gessner ’ s procedures — that is, transferring titles onto one side of a piece of paper before copying them into tabular form. Yet he optimizes this process by dint of a small refi nement, with regard to the paper itself: instead of copying data onto specially cut octavo sheets, he uses uniformly and precisely cut paper whose ordinary purpose obeys the contingent pleasure of being shuffl ed, ordered, and exchanged: “ cartes à jouer. ” 35 In sticking strictly to the playing card sizes available in prerevolutionary France (either 83 × 43 mm or 70 × 43 mm), Rozier cast his bibliographical specifi cations into a standardized and therefore easily handled format.