INDAGINI DIAGNOSTICHE PROPEDEUTICHE AL RESTAURO DELLA SALA DEI VENTI DI PALAZZO DEI NORMANNI A PALERMO

La Sala dei Venti è uno dei più suggestivi luoghi del Palazzo dei Normanni a Palermo, si tratta di una struttura sita all’interno della Gioaria, una torre medievale dell’originale nucleo arabo-normanno, antistante la Sala di Ruggero, coperta da un soffitto ligneo dipinto, risalente al XVIII secolo, al centro del quale campeggia una rosa dei Venti che dà il nome all’ambiente. Le porzioni superiori delle pareti e la copertura, soggette nel tempo a numerosi restauri e rifacimenti, presentano una ricca decorazione dipinta suddivisa in tre livelli: quello superiore costituito dal soffitto dipinto (parzialmente incamottato); quello intermedio costituito dai dipinti murali con decorazioni a finto marmo; il livello inferiore costituito da dipinti murali con decorazione a finto mosaico su fondo argentato-dorato. Sfortunatamente grandi estensioni delle superfici decorate versano in cattive condizioni di conservazione, principalmente a causa di pregresse infiltrazioni d’acqua dal tetto, che hanno generato importanti dilavamenti degli strati pittorici e di preparazione, distacchi e cadute, soprattutto sul soffitto dipinto e su due delle quattro pareti decorate a finto mosaico. Per salvaguardare questo patrimonio, l’Assemblea Regionale Siciliana (ARS) ha previsto un intervento di restauro, avendo efficacemente risolto il problema delle infiltrazioni con il rifacimento del sistema di copertura. Preliminarmente alla stesura del progetto di restauro, l’ARS ha avviato un sistematico studio diagnostico e conoscitivo dei materiali qui presentato. Sono state quindi eseguite indagini non invasive e non distruttive in situ e indagini micro-distruttive su campioni prelevati ad hoc volte a definire la composizione materiale e i fenomeni di degrado in atto, dovuti sia alle condizioni termoigrometriche non favorevoli, all’invecchiamento dei materiali e alle pregresse intese infiltrazioni delle acque piovane. L’osservazione preliminare e l’indagine termografica hanno confermato l’assenza in atto di infiltrazioni d’acqua, definitivamente risolte dalla nuova copertura, e di fenomeni di condensa sulle superfici dipinte, anche grazie alla presenza di griglie di aerazione su più livelli. Inoltre, l’incrocio dei dati termografici e quelli dei rilievi tramite pacometro ed endoscopio ha messo in evidenza la struttura del tetto e permesso di individuare i sistemi di connessione tra le tavole. Le indagini XRF, Raman e FT-IR hanno portato all’identificare dei materiali pittorici, originali e di restauro. Il riconoscimento dei pigmenti ha fornito un supporto per la datazione indiretta delle fasi originali e dei successivi interventi. Le ridipinture sono a base di una resina alchidica, identificata in GC-MS. Le stesure pittoriche originali del soffitto ligneo sono risultate essere a base di una tempera a uovo, applicata su uno strato di preparazione a gesso e colla animale; le dorature sono in foglia d’oro. Anche le specie lignee e le fibre tessili dell’incamottatura sono state identificate. Lo studio del livello intermedio a finto marmo ha evidenziato la presenza di decori geometrici in buono stato di conservazione occultati da fasce di carta con stesura grigio-bianca a base di bianco di titanio intervallate da cornici lignee a falso oro. Infine, per i dipinti murali del terzo livello, le indagini hanno evidenziato la presenza di una diversa stratigrafia ed in particolare di uno strato bituminoso presente al di sotto dello strato pittorico nelle porzioni più degradate. L’indagine di fluorescenza UV e FT-IR ha localizzato e identificato, su alcune superfici, la presenza diffusa di una resina chetonica di restauro in corrispondenza di una parete che mostrava un peculiare fenomeno di crettatura. Le indagini, che costituiscono ad oggi il primo studio scientifico sui materiali degli apparati decorativi della Sala dei Venti, hanno permesso di ricavare informazioni utili per la programmazione dell’intervento di restauro, ma anche per la ricostruzione degli interventi pregressi e delle fasi cronologiche di realizzazione dell’oper

Multispectral Imaging and p-XRF for the Non-Invasive Characterization of the Anonymous Devotional Painting ‘Maria Santissima delle Grazie’ from Mirabella Imbáccari (Sicily, Italy)

This work presents the results of the in situ, non-invasive diagnostic investigations performed on the canvas oil painting depicting Madonna and Child, venerated as ‘Maria Santissima delle Grazie’ by the local religious community. The work of art (72 cm × 175 cm) is located on the high altar of the main Church in Mirabella Imbáccari, near Catania (Sicily, Italy). The painter is anonymous, and the supposed dating is the late eighteenth century. Although the painting has never been studied before, it has been attributed to a Sicilian workshop in the literature, raising the doubts of the art historian who conducted this study and who hypothesized a Neapolitan manufacture. Furthermore, due to the good conservation state detected by a macroscopic examination, doubts also arose about dating. To shed light on these aspects, a technical-scientific examination proved necessary. Multispectral imaging techniques (IR Reflectography, UV-induced visible Fluorescence, X-ray) are carried out for the study of the execution technique, the identification of underlying remakes, sketch drawing and the evaluation of the conservation conditions. XRF spectrometry analysis is performed for the identification of the chemical elements constituting the pigments (inorganic chromophores). The diagnostic results allowed this research to confirm the dating suggested by the historical-stylistic knowledge and to highlight new technical peculiarities supporting the attribution to a Neapolitan workshop

MATERIALS AND ARTISTIC TECHNIQUES OF THE FLEMISH WOODEN ALTAR FROM DEPOSITS OF ABATELLIS PALACE MUSEUM (PALERMO, ITALY)

In the frame of the restoration intervention on a 16th century wooden altar performed by the experts of the Gallery of Art for the Sicilian Region ‘Palazzo Abatellis’, a deep scientific investigation of the artwork has been made by a scientific team in order to individuate the constitutive materials and techniques. The outcomes from the multi-analytical analyses supported the scheduling and monitoring of the conservation treatments and revealed the pictorial materials and underdrawing techniques typical of the artistic production for this typology of work of art widespread between the 15th and 16th centuries in central and northern Europe

Microclimatic Monitoring for Archeological Shelters Across Indoor Comfort and Conservation: The Case Study of the Villa del Casale in Piazza Armerina (Sicily, Italy)

Conservation and use raise priority and complementary needs in the archeological built heritage and, within the contemporary paradigm, they are no longer conflictual activities. The minimum intervention principle and compatibility are key objectives to avoid altering the values of the heritage. However, the musealization process also requires a double focus: on the one hand, the conservation of the material asset; on the other, the well-being of the users. The influence of environmental parameters on material decay is a well-known item: this occurs through chemical, physical, and biological processes, which contribute to reducing the expected life of archeologi- cal finds. Furthermore, the conditions of thermo-hygrometric comfort are necessary to guarantee the correct use of the site. The paper focuses on the thermo-hygrometric well-being in archeological sites and, in particular, on the case of Villa Romana del Casale, in Piazza Armerina, Sicily, which is a UNESCO site. A complex restoration project was performed on this site a few decades ago, aimed at improving the conservation of the mosaic apparatuses and users’ well-being, through the redesign and consequent replacement of the shelter system. The microclimate monitoring, aimed to verify the environmental conditions created by the new covering system, has been focused on sample room, on which the new covering system has been completed, and rooms that still are covered by the methacrylate old system. The comparison between the environmental parameters related to the old covering system, which caused undesired effects both for use and conservation, and the data related to the new covering system, allowed verifying the improvement in microclimatic conditions after the intervention. Data have demonstrated that the new one has reduced temperature inside the rooms and has increased humidity values. These analytical data demonstrate that the conservative intervention provided a positive impact on microclimatic conditions. Indeed, the comparison also showed the absence of the dangerous greenhouse effect. The conclusion of the paper will propose a comparative analysis of these results and other general aspects of the quality of the intervention, which cannot be measured or can only be measured indirectly

European <i>Smalt</i> in 17th-Century Japan: Porcelain Decoration and Sacred Art

Japanese art tradition, contrary to the case of China, is characterized by an efficient and continued, although mostly undocumented, use of smalt from the late 16th century onward. Recent studies have successfully identified this pigment, the cobalt-colored glass that spread throughout the Old Continent during the Renaissance period, as the coloring agent employed for overglaze-blue enameling on Japanese porcelains produced at the kilns of Arita (the porcelain production center of Japan) from the early 1640s until the 20th century. Fragmentary evidence of the use of smalt in Japanese sacred art has also been reported, yet its earliest incorporation into such a type of traditional art form could not be identified. In order to resolve this crucial issue, portable EDXRF was employed for the non-destructive analyses of Japanese porcelains and sacred images bearing blue decoration. Scientific analysis allowed, for the first time ever, to establish a clear timeline of smalt use. Furthermore, this evidence and the literature data both agree, leading to the identification of the origin of the blue material used on both art productions

Climate and Cultural Heritage: The Case Study of “Real Sito di Carditello”

A monitoring campaign performed on the Real Site of Carditello (found in the commune of San Tammaro, province of Caserta, Italy) was aimed to evaluate the parameters related to air quality and then to control and prevent the degradation risk. The analyses were carried out in the context of the project &ldquo;Innovative methods and technologies for the conservation, valorisation and use of cultural heritage: environmental and archaeological analyses&rdquo;, within the CULTURA CREA-MIBAC program, which aims to provide innovative methods for conservation and enhancement of cultural heritage through environmental and archaeometric analyses. Preliminarily, using field equipment, non-destructive investigations were carried out to identify constituent, restoration, and/or degradation materials belonging to the wall paintings on the main floor and to assess their conservation state under the current environmental conditions. Environmental monitoring was performed both outdoor (to assess the effects of atmospheric pollution and changes in the climate of the structure) and indoor the rooms of the site (to evaluate the conditions of conservation and fruition). The collected data are reported in a web platform, where one can check the real time monitoring data. The platform integrates both environmental data and information regarding the "health status" of site in order to provide a detailed analysis useful for its protection

Comparison between mercury intrusion porosimetry and nuclear magnetic resonance relaxometry to study the pore size distribution of limestones treated with a new consolidation product

Pore-space properties, such as pore-size distribution and connected porosity, are relevant factors in the evaluation of the performance of a consolidation treatment. In this study, two different techniques – Mercury Intrusion Porosimetry (MIP) and Nuclear Magnetic Resonance Relaxometry (NMRR) – were adopted to study the compatibility and the efficacy of a new consolidation product for limestones. This work aims at comparing and combining data obtained by MIP and NMRR; to confirm the relationship between the quantitative results of MIP and the qualitative ones of NMRR, a calibration which leads to correlate T2 distribution and pore size distribution has been applied. Experimental results showed that, in most cases, NMRR results agree with MIP data. Therefore, NMRR technique can be considered a powerful tool to evaluate the change in pore size distribution due to the application of a consolidating agent on stone, especially in cases when sampling should be avoided