Metropolitan Museum curators William M. Ivins and his protégé A. Hyatt Mayor not only assembled a vast collection of prints, from Renaissance masterworks to ephemeral works, but also expanded the appreciation of prints as aesthetic objects, socio-historical documents, and tools of communication. More radically, by discussing these prints in accessible language, they changed our notions of how art reaches the wider public. Drawing on previously unpublished material, including personal letters and departmental records, this is the first comprehensive exploration of the lives, careers, theories, and influence of Ivins and Mayor. Also included are 120 exceptional prints that represent the breadth and depth of their acquisitions, including works by Dürer, Rembrandt, Callot, Goya, Whistler, Cassatt, and Toulouse-Lautrec.