Petrographic and Chemical Characterization of the Frescoes by Saturnino Gatti (Central Italy, 15th Century)

Abstract

This study presents the petrographic and chemical characterization of the frescoes in the Church of San Panfilo in Tornimparte (AQ, Italy) by Saturnino Gatti, a prominent painter of the late 15th–early 16th century, known for his exquisite technique, composition, and use of color. The characterization of the frescoes is essential for understanding the materials and techniques used by Gatti, as well as for identifying the stratigraphy and painting phases. Eighteen samples were collected from the original paint layers, later additions (17th century), and restored surfaces, and analyzed by optical microscopy, cathodoluminescence microscopy, scanning electron microscopy (SEM-EDS), μ-Raman, and electron paramagnetic resonance (EPR). The analyses revealed a microstratigraphy often made of three main layers: (1) preparation, consisting of lime plaster and sand; (2) pigmented lime, applied by the fresco technique; and (3) additional pigmented layer on the surface. The most often recurring pigments are black, red, yellow (all generally linked with the fresco technique), and blue (applied “a secco”). The presence of two painting phases was also noted in one sample, probably resulting from a rethinking or restoration. These findings contribute to the understanding of the history and past restoration works of this cultural heritage site, providing important insights not only for conservators and restorers, but also for a broader understanding of Italian fresco painting and art history of the late 15th and early 16th centuries.

Special Issue: Results of the II National Research Project of AIAr: Archaeometric Study of the Frescoes by Saturnino Gatti and Workshop at the Church of San Panfilo in Tornimparte (AQ, Italy)

“…The bad state of conservation of these paintings could also be due to previous invasive restorations that affected the surfaces with heavy retouching and repainting. This is especially observed close to the openings of panel A and panel C, where modern mortar-based materials have been used, probably leading to the occurrence of the observed degradation phenomena [18]. After the investigations centred in the characterisation of the degradation phenomena, a diagnostic study was conducted aimed at the characterization of the executive techniques over the time, with particular attention being paid to the preparatory drawings, the original materials of the draft fresco and the occurrence of "a secco" finishes still present, both inorganic (pigments and plasters) and organic (binders and additives in the plasters or in the dry application to define the details of the representations).…”

“…The monitoring of the thermo-hygrometric conditions within the site was th Other retouches almost certainly took place at the same time, for which zinc was used and therefore cannot be dated before the mid-19th century [17]. An interesting aspect that emerges from the surveys is the possibility of recognising consequently preserving the finishing touches applied "a secco": the petrographi chemical studies have demonstrated the tendency of Saturnino to apply colour correc onto the dry plaster [18]. During the restoration phase, the cleaning should be approached with particula and caution to remedy the serious errors of evaluation that were repeated in the cle operations executed in the 1950s and 1972 [19], because of which many exquisite d were removed due to the use of excessively invasive products.…”

“…The microcl Other retouches almost certainly took place at the same time, for which zinc white was used and therefore cannot be dated before the mid-19th century [17]. Another interesting aspect that emerges from the surveys is the possibility of recognising and consequently preserving the finishing touches applied "a secco": the petrographic and chemical studies have demonstrated the tendency of Saturnino to apply colour corrections onto the dry plaster [18].…”

“…The strong synergy between the in situ/non-invasive analyses [16] and the imaging techniques survey [17,21] performed on the same pictorial areas allowed an analysis of the quality of the punctual analyses results, demonstrating how a well-designed non-invasive campaign can drastically reduce the amount of sampling [18,19,24,25] necessary to obtain complete information on the materials and the artist's technique.…”