User-Friendly Software for Identifying Moldmates and Twins in Antique Laid Paper: Case Study of a Disbound Blank Book

This progress report details the imaging and initial analysis of watermarks and countermarks present in antique, laid paper leaves from a partial, disbound blank book in the study collection of the Conservation Center at the Institute of Fine Arts at NYU. Preliminary review of watermark catalogues indicates that the paper, featuring the coat-of-arms of Le Tellier of three stars over three lizards, and a countermark reading “H. J. Cusson,” dates roughly from the late seventeenth to early eighteenth centuries. Of the approximately 115 sheets, 20 were analysed using software developed by William A. Sethares (University of Wisconsin, Madison) and C. Richard Johnson, Jr. (Cornell University) to reliably predict whether individual papers were likely to have been made by the same papermaking mold. The programs allowed for the comparison of watermark and countermark shapes by comparison of the ratios of their internal proportions (WatermarkMarker), and the generation of animated overlay .gifs that fade from one image to the next, for instant visual comparison (WatermarkPointMarker and VisualizeOverlays). The incidence of watermarks and moldmates in the folios were also mapped using the VisCodex online collation visualization tool, developed by the University of Toronto Libraries, in collaboration with Dot Porter and Alberto Campagnolo. The results suggest that the stack of sheets was made from two papermaking molds, making the papers moldmates and twins. The progress report concludes with a hypothesis as to which watermark was connected to which countermark, and suggests that the connections between half-sheets may be more easily recreated after more sheets have been analyzed both visually, and with the software.