The title page from Des Principes de l'architecture, de la sculpture, de la peinture, et des autres arts qui en dépendent: Avec un dictionnaire des termes propres à chacun de ces arts, by André Félibien, published in 1697. By comparing current analytical results with period treatises such as this late 17th-century work, conservators can acquire new insights into artists' materials and techniques. Photo: Courtesy Special Collections, Research Library at the Getty Research Institute.