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The conservation of artworks requires a profound knowledge about pictorial materials, their chemical and physical properties and their interaction and/or degradation processes. For this reason, pictorial materials databases are widely used to study and investigate cultural heritage. At Centre for Conservation and Restoration La Venaria Reale (CCR) we prepared a set of about 1200 mock-ups with 173 different pigments and/or dyes, used across all the historical times or as products for conservation, 4 binders, 2 varnishes and 4 different materials for underdrawings. In collaboration with the Laboratorio Analisi Scientifiche (LAS) of Regione Autonoma Valle d'Aosta, the National Institute of Metrological Research (INRIM) and the Department of Architecture and Design (LAMSA) of the Polytechnic of Turin, we created a scientific database that is now available online (http://www.centrorestaurovenaria.it/en/areas/diagnostic/pictorialmaterials-database) designed as a tool for heritage science and conservation. Here we present a focus on materials for pictorial retouching where the hyperspectral imaging (HSI) application, conducted with a prototype of new technology, allowed to provide a list of pigments that could be more suitable for conservation treatments and pictorial retouching. Then we present the case study of the industrial painting Notte Barbara (1962) by Pinot Gallizio where the use of the database including modern and contemporary art materials showed to be very useful and where the fibre optics reflectance spectroscopy (FORS) technique was decisive for pigment identification purpose. Later in this research, the mock-ups' will be exploited to study degradation processes, e. g. the lightfastness, or the possible formation of interaction products, e.g. metal carboxylates.1 Mowilith DM5: PVAc and acrylic ester in aqueous solution, plasticizer free, Sinopia SAS datasheet [21]. 2 Linseed oil was also used as binder for gamboge, madder and indigo, as reported in literature.

Diagnostic physical methods are increasingly applied to Cultural Heritage both for scientific investigations and conservation purposes. In particular, the X-ray imaging techniques of computed tomography (CT) and digital radiography (DR) are non-destructive investigation methods to study an object, being able to give information on its inner structure. In this paper, we present the results of the X-ray imaging study on an ancient Egyptian statuette (Late Period 722–30 BCE) belonging to the collection of Museo Egizio in Torino and representing an Egyptian goddess called Taweret, carved on wood and gilded with some colored details. Since few specific studies have been focused on materials and techniques used in Ancient Egypt for gilding, a detailed investigation was started in order to verify the technical features of the decoration in this sculpture. Specifically, DR and CT analyses have been performed at the Centro Conservazione e Restauro “La Venaria Reale” (CCR), with a new high resolution flat-panel detector, that allowed us to perform tomographic analysis reaching a final resolution better than the one achievable with the previous apparatus operating in the CCR.

The neu_ART project aims at developing state of the art transmission imaging and computed tomography techniques, applied to art objects, by using neutrons as well as more conventional X-rays. In this paper a facility for digital X-ray radiography of large area paintings on canvas or wooden panels and for the X-ray tomography of large size wooden artifacts, recently installed in a protected area, is presented. The results of a K-edge radiography facility that will soon be installed in the same area are also shown.

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The multidisciplinary and multi‐technical study of the coffin lid of Neskhonsuennekhy (Turin, Museo Egizio, inventory number S.05245) datable to the 26th dynasty (664–525 BC) was launched in 2015 at the Centro Conservazione e Restauro La Venaria Reale during the conservation activities required by the Museo Egizio, as part of wider research on the so‐called red coffins. Widespread abrasions and gaps in the pictorial stratigraphy strongly impeded the reading of the decoration, and a reddish and locally blackened material was covering many areas. Integrating multispectral imaging (UV fluorescence, VIL, IR reflectography), MA‐XRF, radiography, and analyses on micro‐samplings (OM, SEM‐EDX, FT‐IR) allowed deepening the state of preservation, detecting previous intervention, and characterizing the blackened surface, necessary to define the cleaning intervention objectives. In particular, the IR reflectography allowed recovering the readability of the beautiful drawings and the ancient hieroglyphs hidden beneath the reddish blackened surface. Based on the analytical data and compatibility with the pigments known in ancient Egypt, it was possible to return to the public the original lost decoration with a descriptive and virtual reconstruction. The new LANDIS‐X scanning station equipped with a real‐time macro XRF was fundamental for studying pigments, glazes, and mixtures besides the presence of lead impurities in the copper source used to make the Egyptian blue pigment, encouraging the research on the sources of mineral supply. Finally, this study allowed understanding the technique of execution of the find, from the assembly of the wooden elements to the reddish finish, noticing analogies with the other red coffins.

Digitalization techniques, such as photogrammetry (PG), are attracting the interest of experts in the cultural heritage field, as they enable the creation of three-dimensional virtual replicas of historical artifacts with 2D digital images. Indeed, PG allows for acquiring data regarding the overall appearance of an artifact, its geometry, and its texture. Furthermore, among several image-based techniques exploited for the conservation of works of art, multispectral imaging (MSI) finds great application in the study of the materials of historical items, taking advantage of the different responses of materials when exposed to specific wavelengths. Despite their great usefulness, PG and MSI are often used as separate tools. Integrating radiometric and geometrical data can notably expand the information carried by a 3D model. Therefore, this paper presents a novel research methodology that enables the acquisition of multispectral 3D models, combining the outcomes of PG and MSI (Visible (VIS), Ultraviolet-induced Visible Luminescence (UVL), Ultraviolet-Reflected (UVR), and Ultraviolet-Reflected False Color (UVR-FC) imaging) in a single coordinate system, using an affordable tunable set-up and open-source software. The approach has been employed for the study of two wooden artifacts from the Museo Egizio di Torino to investigate the materials present on the surface and provide information that could support the design of suitable conservation treatments.

This contribution focuses on the conservation of an Egyptian wooden sculpture (Inventory Number Cat. 745) belonging to the Museo Egizio of Torino in northwest Italy. A preliminary and interdisciplinary study of constituent painting materials and their layering is here provided. It was conducted by means of a multi-technique approach starting from non-invasive multispectral analysis on the whole object, and subsequently, on selected micro-samples. In particular, visible fluorescence induced by ultraviolet radiation (UVF), infrared reflectography (IRR) and visible--induced infrared luminescence were used on the whole object. The micro-samples were analysed by means of an optical microscope with visible and UV light sources, a scanning electron microscope (SEM) with an energy-dispersive X-ray spectrometer (EDX), Fourier transform infrared (FT-IR) spectrometer, pyrolysis-gas chromatography/mass spectrometer (Py-GC/MS) and micro-particle induced X-ray emission (PIXE). The characterization of the painting materials allowed the detection of Egyptian blue and Egyptian green, and also confirmed the pertinence of the top brown layer to the original materials, which is a key point to design a suitable surface treatment. In fact, due to the water sensitiveness of the original materials, only few options were available to perform cleaning operations on this artwork. To setup the cleaning procedure, we performed several preliminary tests on mockups using dry cleaning materials, commonly used to treat reactive surfaces, and innovative highly water retentive hydrogels, which can potentially limit the mechanical action on the original surface while proving excellent cleaning results. Overall, this study has proved fundamental to increase our knowledge on ancient Egyptian artistic techniques and contribute to hypothesize the possible provenance of the artefact. It also demonstrated that polyvinyl alcohol-based retentive gels allow for the safe and efficient cleaning of extremely water sensitive painted surfaces, as those typical of ancient Egyptian artefacts.