Cultural heritage: First hi-tech monitoring project for Palazzo Chigi in Rome area

First hi-tech monitoring project to evaluate the ‘health conditions’ of paintings, frescos, marble busts and the leather wall cladding of Palazzo Chigi in Ariccia (Rome). A team of ENEA researchers has deployed advanced technologies to study the artistic and cultural heritage embodied by this famous building which provides the scenic backdrop for the monumental Piazza di Corte (designed by Gian Lorenzo Bernini).

The results shall be presented tomorrow during the event “Le tecniche diagnostiche utilizzate a Palazzo Chigi di Ariccia” (the diagnostic techniques adopted at Palazzo Chigi in Ariccia) organized by ENEA (15 November - 3.30 pm - Palazzo Chigi - Piazza della Corte, Ariccia, Rome).

The activities regarding the works of Palazzo Chigi make up a part of the ADAMO project (Analisi, DiagnosticA e MOnitoraggo) − coordinated by ENEA and funded by the Distretto Tecnologico per i Beni Culturali (cultural heritage technological district) of the Lazio regional authority − the aim being to make diagnostic technologies available to small and medium-sized enterprises in the Lazio region for the recovery and enhancement of cultural assets such as those to be found along the Appia and Tuscolana consular roads.

Among the investigation techniques, laser-induced fluorescence and Raman spectroscopy were adopted, enabling study of the patina on the marble busts of the Bernini school and monitoring of the possible onset of ‘efflorescence' on works of art on which colour changes have been noted. In addition, ENEA implemented the RGB-ITR laser system, with its three beams of light (red, green and blue) deployed in order to acquire information on the surface colour and structure. Already used for the Sistine Chapel and the Loggia of Cupid and Psyche, this laser system enables 3D reconstruction of works of art, with acquisition at a distance of up to 30 meters – without the use of scaffolding – for preliminary examination of any damage urgently in need of intervention.

Moreover, the method is unaffected by scarcity or variation of light and the whites are balanced at any distance. “The laser systems designed in our laboratories came about due to the need to back up many of the case studies that may present problems during the diagnostic stage using the technologies available in today’s marketplace.

Thanks to its ability to perform a complete rotation of 360°, for example, the RGB-ITR system enabled us to reconstruct a large space such as the reception room that hosts the series of preparatory cartoons for the mosaics of St. Peter’s Dome, by Giuseppe Cesari, also known as the Cavalier d’Arpino, the late-mannerist painter whose studio was frequented by the young Caravaggio for almost a year”, explains Massimiliano Guarneri of ENEA’s diagnostics and metrology laboratory. During this measurement campaign, two works by the seventeenth-century painter Mario De Fiori – “Self-portrait” and “Spring” – were also acquired by the scanner, which presented some problems regarding realization of the pertaining 3D models, due to light reflections from the sources used to illuminate the painted surface. An IR-ITR scanner was also used during these measurement operations, based on the same technology as the RGB-ITR but with a laser source of different wavelength.

This enabled detection, in “Spring”, of hitherto unknown “pentimenti” (or ‘false starts’) − i.e. corrections made during the work on the canvas. Palazzo Chigi di Ariccia is one of the few historic palazzos that still retain painted and decorated wall claddings in leather, serving both as an adornment and as thermal insulation. For this type of material, ENEA has used a portable THz radiation device, capable of penetrating the surface of non-metallic materials, such as leather in this case. “From preliminary measurements carried out on cladding samples, both in the laboratory and directly in the Cardinal’s rooms, we detected ‘anomalies’ not visible to the naked eye, attributable to layers painted with metallic pigments, then covered with other layers.

This is not the first time that we have ‘tested’ the effectiveness of our prototype. Our technology had already been used at the Uffizi gallery in Florence on an ‘affresco su tavella’ (literally, a tile fresco) by Alessandro Gherardini, a famous painter of the early 1700s”, notes Emilio Giovenale of Laboratorio ENEA di Sorgenti, Antenne e Diagnostiche (the ENEA sources, antennas and diagnostics laboratory).

For further information:

Progetto ADAMO http://progettoadamo.enea.it/progetto/

Event “Le tecniche diagnostiche utilizzate a Palazzo Chigi di Ariccia” (15 November – 3.30 p.m. - Palazzo Chigi - Piazza della Corte, Ariccia, Roma) http://progettoadamo.enea.it/wp-content/uploads/2019/11/flyer-workshop-Ariccia-v5-DEF.pdf