Study of Works on Parchment
In order to begin to address the question of whether material analysis could distinguish the hand of Pacino di Bonaguida from that of his collaborator, the Master of the Dominican Effigies, the three leaves from the Laudario of Sant'Agnese in the collection of the J. Paul Getty Museum were subjected to in-depth study. Using only noninvasive analytical techniques, GCI scientists carefully characterized the pigments used to paint each illumination. X-ray fluorescence (XRF) spectroscopy, Raman spectroscopy, and multispectral imaging provided a measure of the chemical elements and molecular composition in examined areas, as well as the likely distribution of pigments across the illuminations.
From these initial studies, a picture began to emerge of the pigment palette used to create each illumination. Perhaps not surprisingly, the results suggested the two artists employed very similar palettes, consisting of common fourteenth-century pigments, such as vermilion, red lead, azurite, and ultramarine. By focusing over an extended period of time on works in the Getty's collection, researchers were able to develop an analytical protocol, refine the questions being addressed, and build a foundation for additional studies.
The Fitzwilliam Museum and Queens' College Laudario Leaves
The Laudario of Sant'Agnese was broken up in the early nineteenth century. Some of the leaves survive intact, but in some cases the miniatures were cut from the full leaves, and the fragments scattered to public and private collections around the world. In 2009 Stella Panayotova of the Fitzwilliam Museum published an article describing the rediscovery of four miniatures from the Laudario at Queens' College and the Fitzwilliam Museum, bringing the total number of extant fragments to twenty-eight.
Queens' College and the Fitzwilliam Museum agreed to bring these newly discovered miniatures, together with two additional leaves in the collection of the Fitzwilliam Museum, to the Getty for inclusion in this study. Using the same noninvasive analyses as were used on the three Getty Laudario leaves, the pigments and colorants used to create the illustrations were examined, further building a database of the materials and application methods employed by Pacino and his workshop.
The reverse sides of several of the Cambridge leaves, where the folio number would have been written, were obscured by the remnants of paper backings. X-radiography—a technique more commonly employed for the study of paintings than manuscript illuminations—was used to reveal the foliation, which helped confirm and revise curatorial understanding of the original order of the leaves. Interestingly, the radiographs also yielded information about the painting techniques used to create the miniatures, which could then be compared to Pacino's work on panel.
Works on Parchment in Other Collections
To further extend the scope of the study, leaves or fragments from the Laudario and other manuscripts illustrated by Pacino, his collaborators, and his contemporaries held in other collections were identified for inclusion in this study. Using a portable XRF spectrometer and portable microscope, an additional ten objects were examined in situ.