Motherwell catalogue raisonné co-author Katy Rogers spoke on the panel, “Authenticity and the Appraiser,” at the Appraisers Association of America National Conference on November 10, 2012. She discussed the ways in which the long-term, in-depth research that goes into a catalogue raisonné leads to a greater understanding of an artist’s working method, and the way this in turn informs judgments about authenticity. She showed examples of complex layers of repainting in Motherwell’s works which were discovered with the help of conservation scientists, including fragments of destroyed paintings that had found their way onto the market. The evolution of Elegy to the Spanish Republic No. 55 (shown here) is an example of the several states a painting might go through as Motherwell re-worked a composition over time. She gave special emphasis to the way in which a catalogue raisonné project synthesizes information from a variety of sources and draws upon a broad range of expertise in order to ensure that all judgments are based on the most up-to-date, complete research.