I'm a postdoctoral researcher working within the field of heritage science, a cross-disciplinary research area. My research activity is mainly centered on the study of art and archaeological objects using non- and micro-invasive spectroscopic techniques, with a special focus on the analysis of polychrome works of art. Other research interests include topics related to spectral databases, data integration, FAIR data management, and open science.
As part of a detailed investigation project focused on the painting materials and technical featu... more As part of a detailed investigation project focused on the painting materials and technical features used in Wallachia during the 17th and 18th century, the imperial icon “Mother of God with Child” from the Orthodox Church of the “Annunciation” in Râmnicu Vâlcea, Romania, was investigated before the restoration intervention. A minimally invasive multi-analytical approach consisting of high-resolution digital radiography, hyperspectral imaging, UV fluorescence imaging, portable X-ray fluorescence, and Fourier transform infrared spectroscopy was used. The results emphasized several key features, such as: the structure of the wooden panel, the nature of pigments and of the painting technique frequently used at that time, and various defects of the pictorial layer including traces of previous restoration works, most probably made at the end of the 18th century.
This work presents the results of a complementary diagnostic investigation carried out on a late ... more This work presents the results of a complementary diagnostic investigation carried out on a late wooden panel painting attributed to world-famous Renaissance painter Lucas Cranach the Elder. The aim of this study was to characterize the pigments, ground layers and painting technique used in Cranach's painting Madonna and Child by means of an integrated nondestructive approach that included Hyperspectral Imaging (HSI), portable X-ray fluorescence (XRF) and Fourier Transform Infrared Spectroscopy (FTIR). Combined XRF and FTIR data allowed identification of a vibrant color palette, with lead white, verdigris, smalt, vermilion, red earth, yellow ochre, and a zinc-rich brown earth among the used pigments. Hyperspectral imaging showed no underdrawings, but various technical features and past restoration interventions were possible to document. The findings provide valuable artistic and technical information regarding the painting materials and style used by this influential 16th-century master, as well as key information that can support the conservation strategy of this remarkable artwork.
This paper presents the results of an in-depth diagnostic investigation carried out on four Trans... more This paper presents the results of an in-depth diagnostic investigation carried out on four Transylvanian icons originally painted at the beginning of the 18th century and entirely repainted later, in 1911. The icons, originating from a wooden church in Alba County (Romania), were investigated by an array of non-invasive and micro-invasive techniques that included: multi- and hyperspectral imaging, digital radiography, X-ray fluorescence, and Fourier transform infrared spectroscopy. Combined imaging techniques allowed extraction of information from the original pictorial layer and highlighted the original inscriptions. Spectroscopic analysis carried on micro-samples identified many traditional pigments used in Byzantine iconography such as: lead white, red lead, orpiment, red ochre, yellow ochre, and umber. The presence of zinc white, Prussian blue, and some chromium-based pigments in the upper paint layers was directly associated with the repainting. Information on the used painting technique was also obtained, as well as a series of informative technical details that shed light on the complex history of the icons, while offering at the same time new knowledge on the materials and painting techniques used in Transylvanian workshops, between the 18th and 20th century. Overall results allowed characterization and discrimination of the original painting materials and those present in the repainting, and helped conservators with the restoration of the objects.
The Peleș National Museum in Sinaia, Romania, includes within its collection of musical instrumen... more The Peleș National Museum in Sinaia, Romania, includes within its collection of musical instruments a unique harpsichord of the Taskin workshop. The instrument is representative of the eighteenth century French harpsichords, finished in 1772 by Taskin Pascal, a master instrument-maker of his time. This paper presents the results of a comprehensive diagnostic investigation carried out on the exterior decoration of the harpsichord, by means of multiple non-invasive and micro-invasive analytical techniques: multispectral imaging, X-ray fluorescence (XRF) spectroscopy, laser-induced breakdown spectroscopy (LIBS), Fourier transform infrared spectroscopy (FTIR), and optical microscopy (OM). Imaging investigation highlighted various past interventions and restorations—fillings, consolidation and chromatic reintegration of the paint layer, as well as some interesting details related to the preparatory layer and on the painting technique. Results of the elemental analysis indicated that a rich color palette was used for the luxurious decorations: vermilion for most of the red areas, lead white, a copper-based pigment for the blue and violet hues, along with Prussian blue, chromium oxides for the green tones and possibly emerald green, and iron oxides for the red, yellow and ochre tones. FTIR analysis highlighted the existence of two-layers ground based on the first layer of chalk and animal glue, covered by a second oil-bound layer of lead white. Metal soaps, gypsum, barium sulfate as well as an intermediate sizing layer based on shellac were also identified. Examination of samples’ cross-sections revealed a rich stratigraphy, up to ten layers being highlighted for samples taken from the case sides’ painting. The presence of two gold foils on the gilded areas, one at the top and the other within the intermediate layers, provides clear evidence of later interventions. The corroborated results offer valuable physico-chemical insights on the complex history of this prestigious harpsichord with remarkable aesthetic and historical value, as well as key information for its most suitable restoration approach.
The article presents a multi-analytic investigation of a severely degraded Jewish ritual parchmen... more The article presents a multi-analytic investigation of a severely degraded Jewish ritual parchment coming from a private collection. The main aim of the study was to obtain key information on the parchment manufacturing technique and original materials used, information that could help understand the historical context of the object. To this aim, a series of noninvasive investigations were carried out by means of multi- and hyperspectral imaging, Fourier transform infrared (FTIR) spectroscopy and X-ray fluorescence (XRF) spectroscopy. Specific degradations and mapping of previous conservation treatments could be highlighted via multispectral imaging. Short-wave infrared images indicated the use of both iron gall and carbon black ink, probably one related to the original writing and the other to a later intervention. To improve the imaging of degraded or partially lost text, a linear spectral unmixing classification of the HSI dataset was proposed that showed promising results, allowing it to be applied to similar objects. XRF analysis offered an in-depth view of the chemical fingerprint of the original iron gall ink and critical findings on the existence of other inorganic compounds originating from the parchment manufacture. Registered FTIR data indicated denaturation of the collagen fibers and the presence of fungal-derived calcium oxalates and zinc carboxylates. In accordance with ancient Jewish parchment preparation techniques, the use of calcium sulfate, vegetable tannins, and oils was also inferred from the registered infrared spectra. The corroborated results offer valuable information on the origin, production technology, and overall degradation state of the parchment manuscript. Not least, the findings could be of great interest for conservators and restorers in the field.
In this study several non-invasive and minimally-invasive techniques were employed for the discov... more In this study several non-invasive and minimally-invasive techniques were employed for the discovery of the original aspect of an old iconostasis belonging to a small wooden church in Vâlcea County (southern Romania). Preliminary examination of the iconostasis raised suspicions upon its actual age, the wooden carved decorations style pointing towards the Brancovan period, while images in raking light highlighted old lacunae painted over. Hyperspectral imaging and X-ray Fluorescence investigations were performed in situ, while Fourier-Transform Infrared Spectroscopy and microscopic examination were performed on several microsamples. Corroborated results confirmed the presence of an older painting underneath the visible one. Cross-section analysis revealed the existence of multiple layers, while images acquired with hyperspectral camera revealed contours of the initial drawing. Several pigments were found such as smalt, Prussian blue, vermilion, red lead, red and yellow ochre, chrome yellow, chrome green, lead white and zinc white. A modified egg tempera technique - proteinaceous materials mixed with oil, was most probably originally used. The obtained results shed light on the traditional painting techniques used within the Brancovan period as well as essential information for art historians and conservators involved in the restoration of this valuable artifact.
Journal of Optoelectronics and Advanced Materials, 2020
This paper presents the first set of investigations on the mural paintings belonging to Drăguțeșt... more This paper presents the first set of investigations on the mural paintings belonging to Drăguțești wooden church (1813-1814 A.D.) that has recently been included into the patrimony of Golești Museum, Argeș County. Conservation of a religious site of this type requires a deep analysis of materials in order to evaluate correctly the murals' state of conservation, but also for identifying the proper intervention materials that must have characteristics similar to the original ones. Aside from photographic documentation, molecular characterization was achieved via Fourier-transform infrared spectroscopy, while functional analysis was performed with X-ray diffraction and elemental identification was performed with the help of X-ray fluorescence spectroscopy and laser-induced breakdown spectroscopy, aiming to obtain as much information as possible about the mortars and the pigments. The results showed the plasters from the intonaco and arriccio layers are similar, based on lime and quartz sand mortars, correlating with the traditional execution technique. Regarding the pigments used, the study revealed that cinnabar could have been used as red pigment, synthetic ultramarine as blue pigment, along with other possible iron oxides. Furthermore, a historical restoration was spotted by the detection of polyvinyl acetate. The study is an essential step towards the future restoration intervention that is of absolute necessity.
This paper deals with the development of a multidisciplinary study on the current state of conser... more This paper deals with the development of a multidisciplinary study on the current state of conservation of the facade of the Arciprestal Church of Santa María de Morella (Castellón, Spain), a work of the Gothic period of great historical and artistic value. The aim of this diagnosis was to undertake the preventive conservation actions required and increase the knowledge about the conservation of paintings on stones. During the diagnosis scanning, electron microscopy was demonstrated to be a valuable analytical method for wall paintings on stone. The facade, which since its construction has not undergone major architectural changes, has reached our days as it was configured in its creation, adding the traces of the passage of time and interventions that have suffered polychromies. Because of the conservation situation, it was decided to have an interdisciplinary project for the structural study of the work, an exhaustive study of the materials and their state of conservation. The stu...
Science and Digital Technology for Cultural Heritage - Interdisciplinary Approach to Diagnosis, Vulnerability, Risk Assessment and Graphic Information Models - Proceedings of the 4th International Congress Science and Technology for the Conservation of Cultural Heritage, 2019
The Maqsura and its Mihrab is one of the most outstanding locations of the Mosque-Cathedral of Co... more The Maqsura and its Mihrab is one of the most outstanding locations of the Mosque-Cathedral of Cordoba built during the reign of Caliph Al-Hackam II (962-965 AD). The ART4ART mobile laboratory has allowed to study materials, state of conservation and structure characteristics at Maqsura without sampling. 3D digitization, elementary and molecular physicochemical analysis, Laser Doppler Vibrometer (LDV) and Ground Penetration Radar (GPR) were employed to study mosaics, mural paintings roof and subsoil. 3D digitization using photogrammetry offers the possibility to digitally manipulate the models and observe small details on the surface, but also to analyze the monument degradation in time, by subsequent 3D models of the same areas. GPR and LDV techniques are noninvasive methods to investigate internal structure of the walls or their state of preservation (cracks, detachments). Chemical analysis was used for material identification in situ. This multidisciplinary approach based on non-destructives techniques allows us to study Maqsura materials and its state of conservation in situ and real-time without sampling assay, what makes this approach as a good protocol for the diagnosis of the Cultural Heritage.
Science and Digital Technology for Cultural Heritage - Interdisciplinary Approach to Diagnosis, Vulnerability, Risk Assessment and Graphic Information Models - Proceedings of the 4th International Congress Science and Technology for the Conservation of Cultural Heritage, 2019
The characterization and diagnosis of mural paintings located in Santa María Magdalena Church (Se... more The characterization and diagnosis of mural paintings located in Santa María Magdalena Church (Seville, Spain) were studied by X-ray fluorescence (XRF) and Laser Doppler Vibrometer (LDV). Laser Doppler vibrometer (LDV) is a non-destructive and non-contact technique based on recording the answer of materials to different sound waves in order to evaluate deformations, cracks, blisters, detachments and other damages on painting walls of the chorus. XRF analyses discovered the main materials used by Lucas Valdés in the frescoes of 18th century. The main weathering forms found in the temple after visual inspections are cracks and lacunas, However, LDV could not detect cracks at the ratio volume/distance employed. Further studies must be carried out to improve the use of this methodology in mural paintings.
Science and Digital Technology for Cultural Heritage - Interdisciplinary Approach to Diagnosis, Vulnerability, Risk Assessment and Graphic Information Models - Proceedings of the 4th International Congress Science and Technology for the Conservation of Cultural Heritage, 2019
The purpose of this work was to carry out the diagnosis and vulnerability analysis of the ceramic... more The purpose of this work was to carry out the diagnosis and vulnerability analysis of the ceramic and glazed terracotta tombs of Omnium Sanctorum church (Seville, Spain) by non-destructive techniques such as X-Ray fluorescence (XRF) for chemical analyses of tiles, and 3D digitization to identify the main weathering forms. Efflorescence, detachment, cracks and loss of glazed materials were detected by 3D digitization and compared with the results obtained by in situ inspection, while XRF analysis discovered the composition of tiles without sampling. The combination of these non-destructive techniques allowed to know the composition of the materials and to establish that dampness by capillarity may be the main cause of weathering.
The paper presents a comparative investigation on two icons, dated approximately 17–18th and 19th... more The paper presents a comparative investigation on two icons, dated approximately 17–18th and 19th century, respectively, which are representative for the Russian Lipovan cultural communities. A non-invasive protocol was employed aiming to gain a wider perspective on this type of icons, which had not been studied so far through analytical means. Imaging techniques (multispectral and hyperspectral imaging, along with digital radiography) were used to highlight the conservation issues and the painting technique, pointing out areas where elemental (X-ray fluorescence spectroscopy) and molecular (Fourier-transform infrared spectroscopy) techniques should be applied for more detailed information. Results showed that the wooden panels were in a fairly good conservation status, with only slight traces of xylophagous attack and fine cracks. The succession of the painting layer was obvious, as well as features, which were not visible under normal light condition, such as decorative elements. Silver foil was used for the upper parts of the icons, and in one case, for the garments as well. Both icons had similar features in terms of painting technique, such as the use of gypsum as a preparation layer, followed by a second substrate based on an iron-rich red clay. The color palette included mineral pigments (ochre, red iron oxide, possibly Prussian blue) and metallic pigments (lead white and/or red lead). Previous interventions were highlighted by the presence of barium sulfate. For both icons, egg yolk was most probably the binding medium, which was used. The natural ageing and interference from other compounds led to the degradation of the varnish layer to the point that it could no longer be identified. With no major differences found between the two investigated icons in terms of the painting technique, the results show a remarkable and well-established tradition. The comparison of the two icons is a good example of how analytical techniques can reveal hidden information and determine cultural patterns passed on from generation to generation.
Proceedings of the 11th International Conference on Developments in eSystems Engineering (DeSE), 2018
This paper presents an optimized approach for the characterization of complex painting layers and... more This paper presents an optimized approach for the characterization of complex painting layers and for the evaluation of previous interventions on artworks. Focusing on the capabilities of hyperspectral imaging, which combines spectral and imaging data, this specific approach reflects also the importance of complementary methods and techniques, which have the ability to complete and to validate the results. Following the unique character of the artworks, our goal is to emphasize the importance of data association for the characterization of complex structures such as pictorial layers. The case study for our application was represented by an artwork attributed to a tefan Luchian, one of the most representative Romanian modern artist from the beginning of the 20th century. By combining hyperspectral data with multispectral analysis, high resolution digital X-ray and XRF we were able to develop a multi-step approach that can accurately document the key aspects regarding the state of conservation, the execution technique, and also the features related to previous interventions. Moreover, by correlating the aspects highlighted earlier we were able to use the resulted data for the artwork authentication.
Traditional, historical varnishing techniques applied on ancient musical instruments have been in... more Traditional, historical varnishing techniques applied on ancient musical instruments have been increasingly studied within the last decades, a comprehensive physico-chemical characterization of these coatings being important not only for art historical analysis of artifacts but for proper restoration and conservation treatments as well. In this paper we discuss the chemical composition and micro-structure of materials used in violin varnishes, with a case study focused on a copy of 1712 Antonio Stradivari violin made in 1963 by Romanian master luthiers in Reghin. Defined as a clear, protective layer of organic film-making substances coated onto the surface, musical instrument varnishes are in general various mixtures of natural products - drying oils, essential oils, tree resins, gums, etc. - that may be difficult to analyze due their complex composition and natural variability. The results obtained in our study, on micro-samples without any special pre-treatment, by the use of Fourier Transform Infrared - Attenuated Total Reflectance (FTIR-ATR) Spectroscopy, highlights characteristic absorption bands that indicate the presence of triterpenic resins (possible Dammar) and siccative oils. Additional data on regard the varnish layers and the ground coating are discussed via Scanning Electron Microscopy coupled with X-Ray Analysis (SEM-EDX).
Despite the large number of unguentaria vessels generally discovered in Roman archeological sites... more Despite the large number of unguentaria vessels generally discovered in Roman archeological sites, very little information is available concerning the nature and chemical composition of the products that were originally contained within these artifacts. In this study a combined non-destructive approach that included Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and X-ray fluorescence was used for the characterization of some brownish-black residues preserved in a series of glass unguentaria recovered from excavations at the Roman baths from Mălăiești. The obtained results highlighted the presence of different inorganic substances (an earthbased pigment rich in iron and manganese oxides, admixed with traces of lead-and mercury-based compounds) impregnated with an organic binder such as animal glue and possible natural essential oils, a powdered product associated most probably with a cosmetic/pharmacological use. The study allowed a first insight into the composition and origin of these ancient remains, providing important clues that may help to understand the original function of these unguentaria vessels.
This paper presents an integrated multi-analytical documentation of a bronze vessel discovered in... more This paper presents an integrated multi-analytical documentation of a bronze vessel discovered in a 2nd century Roman military fort from ancient Dacia. The process involved 3D digitization, X-ray and hyperspectral imaging, and molecular, elemental, and structural analysis using Fourier Transform infrared spectroscopy, X-ray fluorescence, laser-induced breakdown spectroscopy and X-ray diffraction. The results of the study revealed the composition of the vessel metal and of the interior coating and the state of conservation through metal quality, internal cracks and corrosion compounds mapping. A 3D virtual reconstruction of the original aspect is also proposed based on the digitization and metal characterization results.
In this study, several wall painting fragments discovered in the Roman baths from the archeologic... more In this study, several wall painting fragments discovered in the Roman baths from the archeological site Alburnus Maior (Roşia Montană, Romania) were analyzed with the aim to investigate the material composition of both plasters and pictorial layers. Dated from the beginning of the second century AD, these rare findings stand among the oldest examples of preserved decorative polychrome paintings on plaster excavated thus far in the former territory of the Roman province of Dacia. A non-destructive multi-analytical approach based on complementary techniques was considered: Fourier transform infrared (FTIR) spectroscopy, X-ray fluorescence (XRF), X-ray diffraction (XRD), UV fluorescence, and hyperspectral imaging (HSI). The obtained results highlight a common Roman color palette mainly based on naturally occurring earth pigments. Red ochre, yellow ochre, manganese-rich ochres/wads, carbon black, and calcite were identified. A traditional two-layer sequence of plasters was found—arriccio (based on lime and siliceous sands), and intonaco (pure lime). The presence of an organic protein binder, identified via FTIR analysis, and sustained by combined imaging documentation, indicates that the pigments were applied a secco. The obtained results are discussed in relation to previous published data, and they can be considered as valuable archeological indicators that contribute to the understanding of the painting techniques and the materials used in the Roman provinces.
This report presents pilot research of archaeological pottery excavated in the Early-Neolithic se... more This report presents pilot research of archaeological pottery excavated in the Early-Neolithic settlement of Chavdar located in the Pirdop-Zlatitsa field, Bulgaria (first half of VI mill BC). The object of investigation is a red-slipped ceramic fragment decorated on both sides with white paint. A multi-analytical approach including optical microscopy, laser-induced breakdown spectroscopy, X-ray fluorescence spectroscopy, and Fourier-transform infrared spectroscopy was undertaken to obtain comprehensive information contributing to the archaeological interpretation. The observations identified the qualitative chemical composition of the ceramic body and the pigment used for the decoration and gave implications on the temperature and the atmospheric conditions at which the vessel has been fired.
International Journal of Architectural Heritage, 2020
This article reports the first analytical study carried on some of the oldest surviving examples ... more This article reports the first analytical study carried on some of the oldest surviving examples of Roman wall paintings, discovered so far on the Romanian territory. Dating back to the second century, these decorative polychrome wall painting fragments were found during an archaeological research carried at Ulpia Traiana Sarmizegetusa, and represent the first mural paintings ever found on site. A set of samples was analyzed using various non-destructive and micro-invasive techniques in order to investigate the material composition and explore the painting technique. The employed methodology allowed for an in-depth characterization of the color palette, generally based on mineral pigments such as red earth, celadonite, yellow ochre, calcite, and strontianite. The absence of organic binders and the possibility to differentiate specific spectral features infer the use of a fresco-secco technique. The results obtained provide important data regarding the artistic and technological skill of ancient painters in this part of the Roman Empire, and they significantly contribute to the research and conservation work carried out at this impressive archaeological site.
This study focuses on the investigation of certain bronze adornment objects from the First Iron A... more This study focuses on the investigation of certain bronze adornment objects from the First Iron Age (the so-called middle Hallstatt period), dating to the ninth–eighth c. BC. These objects are part of a bronze and iron hoard (labeled Cx 116) discovered in the present Romanian territory, at Tărtăria–Podu Tărtăriei vest archaeological site, in Alba County. Along with a second hoard of bronze and iron objects, this represents a unique discovery for the present Romanian territory, namely, for the inner Carpathian area and the Lower and Middle Danube Basin, where no such votive discovery had been made by archaeological excavations. The objects, approximately 450 bronze and iron objects—weapons, tools, adornments, and harnesses—were found in the two hoards, in the Southern ditch, which outlines the archaeological site. Digital radiography has been used to assess the physical state of the objects and to identify potential specific craftsmanship details. It showed a fairly good preservation...
As part of a detailed investigation project focused on the painting materials and technical featu... more As part of a detailed investigation project focused on the painting materials and technical features used in Wallachia during the 17th and 18th century, the imperial icon “Mother of God with Child” from the Orthodox Church of the “Annunciation” in Râmnicu Vâlcea, Romania, was investigated before the restoration intervention. A minimally invasive multi-analytical approach consisting of high-resolution digital radiography, hyperspectral imaging, UV fluorescence imaging, portable X-ray fluorescence, and Fourier transform infrared spectroscopy was used. The results emphasized several key features, such as: the structure of the wooden panel, the nature of pigments and of the painting technique frequently used at that time, and various defects of the pictorial layer including traces of previous restoration works, most probably made at the end of the 18th century.
This work presents the results of a complementary diagnostic investigation carried out on a late ... more This work presents the results of a complementary diagnostic investigation carried out on a late wooden panel painting attributed to world-famous Renaissance painter Lucas Cranach the Elder. The aim of this study was to characterize the pigments, ground layers and painting technique used in Cranach's painting Madonna and Child by means of an integrated nondestructive approach that included Hyperspectral Imaging (HSI), portable X-ray fluorescence (XRF) and Fourier Transform Infrared Spectroscopy (FTIR). Combined XRF and FTIR data allowed identification of a vibrant color palette, with lead white, verdigris, smalt, vermilion, red earth, yellow ochre, and a zinc-rich brown earth among the used pigments. Hyperspectral imaging showed no underdrawings, but various technical features and past restoration interventions were possible to document. The findings provide valuable artistic and technical information regarding the painting materials and style used by this influential 16th-century master, as well as key information that can support the conservation strategy of this remarkable artwork.
This paper presents the results of an in-depth diagnostic investigation carried out on four Trans... more This paper presents the results of an in-depth diagnostic investigation carried out on four Transylvanian icons originally painted at the beginning of the 18th century and entirely repainted later, in 1911. The icons, originating from a wooden church in Alba County (Romania), were investigated by an array of non-invasive and micro-invasive techniques that included: multi- and hyperspectral imaging, digital radiography, X-ray fluorescence, and Fourier transform infrared spectroscopy. Combined imaging techniques allowed extraction of information from the original pictorial layer and highlighted the original inscriptions. Spectroscopic analysis carried on micro-samples identified many traditional pigments used in Byzantine iconography such as: lead white, red lead, orpiment, red ochre, yellow ochre, and umber. The presence of zinc white, Prussian blue, and some chromium-based pigments in the upper paint layers was directly associated with the repainting. Information on the used painting technique was also obtained, as well as a series of informative technical details that shed light on the complex history of the icons, while offering at the same time new knowledge on the materials and painting techniques used in Transylvanian workshops, between the 18th and 20th century. Overall results allowed characterization and discrimination of the original painting materials and those present in the repainting, and helped conservators with the restoration of the objects.
The Peleș National Museum in Sinaia, Romania, includes within its collection of musical instrumen... more The Peleș National Museum in Sinaia, Romania, includes within its collection of musical instruments a unique harpsichord of the Taskin workshop. The instrument is representative of the eighteenth century French harpsichords, finished in 1772 by Taskin Pascal, a master instrument-maker of his time. This paper presents the results of a comprehensive diagnostic investigation carried out on the exterior decoration of the harpsichord, by means of multiple non-invasive and micro-invasive analytical techniques: multispectral imaging, X-ray fluorescence (XRF) spectroscopy, laser-induced breakdown spectroscopy (LIBS), Fourier transform infrared spectroscopy (FTIR), and optical microscopy (OM). Imaging investigation highlighted various past interventions and restorations—fillings, consolidation and chromatic reintegration of the paint layer, as well as some interesting details related to the preparatory layer and on the painting technique. Results of the elemental analysis indicated that a rich color palette was used for the luxurious decorations: vermilion for most of the red areas, lead white, a copper-based pigment for the blue and violet hues, along with Prussian blue, chromium oxides for the green tones and possibly emerald green, and iron oxides for the red, yellow and ochre tones. FTIR analysis highlighted the existence of two-layers ground based on the first layer of chalk and animal glue, covered by a second oil-bound layer of lead white. Metal soaps, gypsum, barium sulfate as well as an intermediate sizing layer based on shellac were also identified. Examination of samples’ cross-sections revealed a rich stratigraphy, up to ten layers being highlighted for samples taken from the case sides’ painting. The presence of two gold foils on the gilded areas, one at the top and the other within the intermediate layers, provides clear evidence of later interventions. The corroborated results offer valuable physico-chemical insights on the complex history of this prestigious harpsichord with remarkable aesthetic and historical value, as well as key information for its most suitable restoration approach.
The article presents a multi-analytic investigation of a severely degraded Jewish ritual parchmen... more The article presents a multi-analytic investigation of a severely degraded Jewish ritual parchment coming from a private collection. The main aim of the study was to obtain key information on the parchment manufacturing technique and original materials used, information that could help understand the historical context of the object. To this aim, a series of noninvasive investigations were carried out by means of multi- and hyperspectral imaging, Fourier transform infrared (FTIR) spectroscopy and X-ray fluorescence (XRF) spectroscopy. Specific degradations and mapping of previous conservation treatments could be highlighted via multispectral imaging. Short-wave infrared images indicated the use of both iron gall and carbon black ink, probably one related to the original writing and the other to a later intervention. To improve the imaging of degraded or partially lost text, a linear spectral unmixing classification of the HSI dataset was proposed that showed promising results, allowing it to be applied to similar objects. XRF analysis offered an in-depth view of the chemical fingerprint of the original iron gall ink and critical findings on the existence of other inorganic compounds originating from the parchment manufacture. Registered FTIR data indicated denaturation of the collagen fibers and the presence of fungal-derived calcium oxalates and zinc carboxylates. In accordance with ancient Jewish parchment preparation techniques, the use of calcium sulfate, vegetable tannins, and oils was also inferred from the registered infrared spectra. The corroborated results offer valuable information on the origin, production technology, and overall degradation state of the parchment manuscript. Not least, the findings could be of great interest for conservators and restorers in the field.
In this study several non-invasive and minimally-invasive techniques were employed for the discov... more In this study several non-invasive and minimally-invasive techniques were employed for the discovery of the original aspect of an old iconostasis belonging to a small wooden church in Vâlcea County (southern Romania). Preliminary examination of the iconostasis raised suspicions upon its actual age, the wooden carved decorations style pointing towards the Brancovan period, while images in raking light highlighted old lacunae painted over. Hyperspectral imaging and X-ray Fluorescence investigations were performed in situ, while Fourier-Transform Infrared Spectroscopy and microscopic examination were performed on several microsamples. Corroborated results confirmed the presence of an older painting underneath the visible one. Cross-section analysis revealed the existence of multiple layers, while images acquired with hyperspectral camera revealed contours of the initial drawing. Several pigments were found such as smalt, Prussian blue, vermilion, red lead, red and yellow ochre, chrome yellow, chrome green, lead white and zinc white. A modified egg tempera technique - proteinaceous materials mixed with oil, was most probably originally used. The obtained results shed light on the traditional painting techniques used within the Brancovan period as well as essential information for art historians and conservators involved in the restoration of this valuable artifact.
Journal of Optoelectronics and Advanced Materials, 2020
This paper presents the first set of investigations on the mural paintings belonging to Drăguțeșt... more This paper presents the first set of investigations on the mural paintings belonging to Drăguțești wooden church (1813-1814 A.D.) that has recently been included into the patrimony of Golești Museum, Argeș County. Conservation of a religious site of this type requires a deep analysis of materials in order to evaluate correctly the murals' state of conservation, but also for identifying the proper intervention materials that must have characteristics similar to the original ones. Aside from photographic documentation, molecular characterization was achieved via Fourier-transform infrared spectroscopy, while functional analysis was performed with X-ray diffraction and elemental identification was performed with the help of X-ray fluorescence spectroscopy and laser-induced breakdown spectroscopy, aiming to obtain as much information as possible about the mortars and the pigments. The results showed the plasters from the intonaco and arriccio layers are similar, based on lime and quartz sand mortars, correlating with the traditional execution technique. Regarding the pigments used, the study revealed that cinnabar could have been used as red pigment, synthetic ultramarine as blue pigment, along with other possible iron oxides. Furthermore, a historical restoration was spotted by the detection of polyvinyl acetate. The study is an essential step towards the future restoration intervention that is of absolute necessity.
This paper deals with the development of a multidisciplinary study on the current state of conser... more This paper deals with the development of a multidisciplinary study on the current state of conservation of the facade of the Arciprestal Church of Santa María de Morella (Castellón, Spain), a work of the Gothic period of great historical and artistic value. The aim of this diagnosis was to undertake the preventive conservation actions required and increase the knowledge about the conservation of paintings on stones. During the diagnosis scanning, electron microscopy was demonstrated to be a valuable analytical method for wall paintings on stone. The facade, which since its construction has not undergone major architectural changes, has reached our days as it was configured in its creation, adding the traces of the passage of time and interventions that have suffered polychromies. Because of the conservation situation, it was decided to have an interdisciplinary project for the structural study of the work, an exhaustive study of the materials and their state of conservation. The stu...
Science and Digital Technology for Cultural Heritage - Interdisciplinary Approach to Diagnosis, Vulnerability, Risk Assessment and Graphic Information Models - Proceedings of the 4th International Congress Science and Technology for the Conservation of Cultural Heritage, 2019
The Maqsura and its Mihrab is one of the most outstanding locations of the Mosque-Cathedral of Co... more The Maqsura and its Mihrab is one of the most outstanding locations of the Mosque-Cathedral of Cordoba built during the reign of Caliph Al-Hackam II (962-965 AD). The ART4ART mobile laboratory has allowed to study materials, state of conservation and structure characteristics at Maqsura without sampling. 3D digitization, elementary and molecular physicochemical analysis, Laser Doppler Vibrometer (LDV) and Ground Penetration Radar (GPR) were employed to study mosaics, mural paintings roof and subsoil. 3D digitization using photogrammetry offers the possibility to digitally manipulate the models and observe small details on the surface, but also to analyze the monument degradation in time, by subsequent 3D models of the same areas. GPR and LDV techniques are noninvasive methods to investigate internal structure of the walls or their state of preservation (cracks, detachments). Chemical analysis was used for material identification in situ. This multidisciplinary approach based on non-destructives techniques allows us to study Maqsura materials and its state of conservation in situ and real-time without sampling assay, what makes this approach as a good protocol for the diagnosis of the Cultural Heritage.
Science and Digital Technology for Cultural Heritage - Interdisciplinary Approach to Diagnosis, Vulnerability, Risk Assessment and Graphic Information Models - Proceedings of the 4th International Congress Science and Technology for the Conservation of Cultural Heritage, 2019
The characterization and diagnosis of mural paintings located in Santa María Magdalena Church (Se... more The characterization and diagnosis of mural paintings located in Santa María Magdalena Church (Seville, Spain) were studied by X-ray fluorescence (XRF) and Laser Doppler Vibrometer (LDV). Laser Doppler vibrometer (LDV) is a non-destructive and non-contact technique based on recording the answer of materials to different sound waves in order to evaluate deformations, cracks, blisters, detachments and other damages on painting walls of the chorus. XRF analyses discovered the main materials used by Lucas Valdés in the frescoes of 18th century. The main weathering forms found in the temple after visual inspections are cracks and lacunas, However, LDV could not detect cracks at the ratio volume/distance employed. Further studies must be carried out to improve the use of this methodology in mural paintings.
Science and Digital Technology for Cultural Heritage - Interdisciplinary Approach to Diagnosis, Vulnerability, Risk Assessment and Graphic Information Models - Proceedings of the 4th International Congress Science and Technology for the Conservation of Cultural Heritage, 2019
The purpose of this work was to carry out the diagnosis and vulnerability analysis of the ceramic... more The purpose of this work was to carry out the diagnosis and vulnerability analysis of the ceramic and glazed terracotta tombs of Omnium Sanctorum church (Seville, Spain) by non-destructive techniques such as X-Ray fluorescence (XRF) for chemical analyses of tiles, and 3D digitization to identify the main weathering forms. Efflorescence, detachment, cracks and loss of glazed materials were detected by 3D digitization and compared with the results obtained by in situ inspection, while XRF analysis discovered the composition of tiles without sampling. The combination of these non-destructive techniques allowed to know the composition of the materials and to establish that dampness by capillarity may be the main cause of weathering.
The paper presents a comparative investigation on two icons, dated approximately 17–18th and 19th... more The paper presents a comparative investigation on two icons, dated approximately 17–18th and 19th century, respectively, which are representative for the Russian Lipovan cultural communities. A non-invasive protocol was employed aiming to gain a wider perspective on this type of icons, which had not been studied so far through analytical means. Imaging techniques (multispectral and hyperspectral imaging, along with digital radiography) were used to highlight the conservation issues and the painting technique, pointing out areas where elemental (X-ray fluorescence spectroscopy) and molecular (Fourier-transform infrared spectroscopy) techniques should be applied for more detailed information. Results showed that the wooden panels were in a fairly good conservation status, with only slight traces of xylophagous attack and fine cracks. The succession of the painting layer was obvious, as well as features, which were not visible under normal light condition, such as decorative elements. Silver foil was used for the upper parts of the icons, and in one case, for the garments as well. Both icons had similar features in terms of painting technique, such as the use of gypsum as a preparation layer, followed by a second substrate based on an iron-rich red clay. The color palette included mineral pigments (ochre, red iron oxide, possibly Prussian blue) and metallic pigments (lead white and/or red lead). Previous interventions were highlighted by the presence of barium sulfate. For both icons, egg yolk was most probably the binding medium, which was used. The natural ageing and interference from other compounds led to the degradation of the varnish layer to the point that it could no longer be identified. With no major differences found between the two investigated icons in terms of the painting technique, the results show a remarkable and well-established tradition. The comparison of the two icons is a good example of how analytical techniques can reveal hidden information and determine cultural patterns passed on from generation to generation.
Proceedings of the 11th International Conference on Developments in eSystems Engineering (DeSE), 2018
This paper presents an optimized approach for the characterization of complex painting layers and... more This paper presents an optimized approach for the characterization of complex painting layers and for the evaluation of previous interventions on artworks. Focusing on the capabilities of hyperspectral imaging, which combines spectral and imaging data, this specific approach reflects also the importance of complementary methods and techniques, which have the ability to complete and to validate the results. Following the unique character of the artworks, our goal is to emphasize the importance of data association for the characterization of complex structures such as pictorial layers. The case study for our application was represented by an artwork attributed to a tefan Luchian, one of the most representative Romanian modern artist from the beginning of the 20th century. By combining hyperspectral data with multispectral analysis, high resolution digital X-ray and XRF we were able to develop a multi-step approach that can accurately document the key aspects regarding the state of conservation, the execution technique, and also the features related to previous interventions. Moreover, by correlating the aspects highlighted earlier we were able to use the resulted data for the artwork authentication.
Traditional, historical varnishing techniques applied on ancient musical instruments have been in... more Traditional, historical varnishing techniques applied on ancient musical instruments have been increasingly studied within the last decades, a comprehensive physico-chemical characterization of these coatings being important not only for art historical analysis of artifacts but for proper restoration and conservation treatments as well. In this paper we discuss the chemical composition and micro-structure of materials used in violin varnishes, with a case study focused on a copy of 1712 Antonio Stradivari violin made in 1963 by Romanian master luthiers in Reghin. Defined as a clear, protective layer of organic film-making substances coated onto the surface, musical instrument varnishes are in general various mixtures of natural products - drying oils, essential oils, tree resins, gums, etc. - that may be difficult to analyze due their complex composition and natural variability. The results obtained in our study, on micro-samples without any special pre-treatment, by the use of Fourier Transform Infrared - Attenuated Total Reflectance (FTIR-ATR) Spectroscopy, highlights characteristic absorption bands that indicate the presence of triterpenic resins (possible Dammar) and siccative oils. Additional data on regard the varnish layers and the ground coating are discussed via Scanning Electron Microscopy coupled with X-Ray Analysis (SEM-EDX).
Despite the large number of unguentaria vessels generally discovered in Roman archeological sites... more Despite the large number of unguentaria vessels generally discovered in Roman archeological sites, very little information is available concerning the nature and chemical composition of the products that were originally contained within these artifacts. In this study a combined non-destructive approach that included Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and X-ray fluorescence was used for the characterization of some brownish-black residues preserved in a series of glass unguentaria recovered from excavations at the Roman baths from Mălăiești. The obtained results highlighted the presence of different inorganic substances (an earthbased pigment rich in iron and manganese oxides, admixed with traces of lead-and mercury-based compounds) impregnated with an organic binder such as animal glue and possible natural essential oils, a powdered product associated most probably with a cosmetic/pharmacological use. The study allowed a first insight into the composition and origin of these ancient remains, providing important clues that may help to understand the original function of these unguentaria vessels.
This paper presents an integrated multi-analytical documentation of a bronze vessel discovered in... more This paper presents an integrated multi-analytical documentation of a bronze vessel discovered in a 2nd century Roman military fort from ancient Dacia. The process involved 3D digitization, X-ray and hyperspectral imaging, and molecular, elemental, and structural analysis using Fourier Transform infrared spectroscopy, X-ray fluorescence, laser-induced breakdown spectroscopy and X-ray diffraction. The results of the study revealed the composition of the vessel metal and of the interior coating and the state of conservation through metal quality, internal cracks and corrosion compounds mapping. A 3D virtual reconstruction of the original aspect is also proposed based on the digitization and metal characterization results.
In this study, several wall painting fragments discovered in the Roman baths from the archeologic... more In this study, several wall painting fragments discovered in the Roman baths from the archeological site Alburnus Maior (Roşia Montană, Romania) were analyzed with the aim to investigate the material composition of both plasters and pictorial layers. Dated from the beginning of the second century AD, these rare findings stand among the oldest examples of preserved decorative polychrome paintings on plaster excavated thus far in the former territory of the Roman province of Dacia. A non-destructive multi-analytical approach based on complementary techniques was considered: Fourier transform infrared (FTIR) spectroscopy, X-ray fluorescence (XRF), X-ray diffraction (XRD), UV fluorescence, and hyperspectral imaging (HSI). The obtained results highlight a common Roman color palette mainly based on naturally occurring earth pigments. Red ochre, yellow ochre, manganese-rich ochres/wads, carbon black, and calcite were identified. A traditional two-layer sequence of plasters was found—arriccio (based on lime and siliceous sands), and intonaco (pure lime). The presence of an organic protein binder, identified via FTIR analysis, and sustained by combined imaging documentation, indicates that the pigments were applied a secco. The obtained results are discussed in relation to previous published data, and they can be considered as valuable archeological indicators that contribute to the understanding of the painting techniques and the materials used in the Roman provinces.
This report presents pilot research of archaeological pottery excavated in the Early-Neolithic se... more This report presents pilot research of archaeological pottery excavated in the Early-Neolithic settlement of Chavdar located in the Pirdop-Zlatitsa field, Bulgaria (first half of VI mill BC). The object of investigation is a red-slipped ceramic fragment decorated on both sides with white paint. A multi-analytical approach including optical microscopy, laser-induced breakdown spectroscopy, X-ray fluorescence spectroscopy, and Fourier-transform infrared spectroscopy was undertaken to obtain comprehensive information contributing to the archaeological interpretation. The observations identified the qualitative chemical composition of the ceramic body and the pigment used for the decoration and gave implications on the temperature and the atmospheric conditions at which the vessel has been fired.
International Journal of Architectural Heritage, 2020
This article reports the first analytical study carried on some of the oldest surviving examples ... more This article reports the first analytical study carried on some of the oldest surviving examples of Roman wall paintings, discovered so far on the Romanian territory. Dating back to the second century, these decorative polychrome wall painting fragments were found during an archaeological research carried at Ulpia Traiana Sarmizegetusa, and represent the first mural paintings ever found on site. A set of samples was analyzed using various non-destructive and micro-invasive techniques in order to investigate the material composition and explore the painting technique. The employed methodology allowed for an in-depth characterization of the color palette, generally based on mineral pigments such as red earth, celadonite, yellow ochre, calcite, and strontianite. The absence of organic binders and the possibility to differentiate specific spectral features infer the use of a fresco-secco technique. The results obtained provide important data regarding the artistic and technological skill of ancient painters in this part of the Roman Empire, and they significantly contribute to the research and conservation work carried out at this impressive archaeological site.
This study focuses on the investigation of certain bronze adornment objects from the First Iron A... more This study focuses on the investigation of certain bronze adornment objects from the First Iron Age (the so-called middle Hallstatt period), dating to the ninth–eighth c. BC. These objects are part of a bronze and iron hoard (labeled Cx 116) discovered in the present Romanian territory, at Tărtăria–Podu Tărtăriei vest archaeological site, in Alba County. Along with a second hoard of bronze and iron objects, this represents a unique discovery for the present Romanian territory, namely, for the inner Carpathian area and the Lower and Middle Danube Basin, where no such votive discovery had been made by archaeological excavations. The objects, approximately 450 bronze and iron objects—weapons, tools, adornments, and harnesses—were found in the two hoards, in the Southern ditch, which outlines the archaeological site. Digital radiography has been used to assess the physical state of the objects and to identify potential specific craftsmanship details. It showed a fairly good preservation...
A stone bead, part of a necklace found in a middle Hallstatt period—type of settlement—the Tărtăr... more A stone bead, part of a necklace found in a middle Hallstatt period—type of settlement—the Tărtăria site in Alba County, Romania, was investigated following a non-destructive approach, by means of energy-dispersive X-ray fluorescence spectrometry and Fourier transform infrared spectroscopy. The highly heterogenous object, found together with numerous bronze and iron objects, appeared to be a variety of chalcedony rich in iron and copper impurities, still preserving clay minerals from the sedimentary matrix in some of the areas. Organic molecules found at the surface of the stone artefact may indicate the presence of a wax or resin residue, possible evidence of early craft specialization. The non-destructive protocol applied allowed an in-depth characterization of the artefact, providing important information not only on the crystal structure but also on the diagnostic impurities present within this peculiar stone bead.
The heritage science sector is facing a critical need for accessible and comprehensive data resou... more The heritage science sector is facing a critical need for accessible and comprehensive data resources to facilitate research, preservation efforts, and interdisciplinary collaboration. The concept of FAIR data management involves embracing principles and practices that ensure that data are Findable, Accessible, Interoperable, and Reusable. This work presents an overview of the latest updates on the INFRA-ART Spectral Library, an open access spectral database of cultural-heritage-related materials that was designed as a digital support tool for heritage research specialists that work with (portable) non- or minimally invasive spectroscopic techniques such as X-ray fluorescence (XRF), attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy, or Raman spectroscopy, among others. The database is an ongoing compilation of high-quality curated data that currently incorporates primary ATR-FTIR and XRF spectra and a preliminary dataset of Raman and short-wave infrared (SWIR) reflectance spectra on over 900 different materials typically found in painted works of art. For increased and sustainable accessibility, the database follows the European Commission’s recommendations on access to scientific information, as well as the FAIR guiding principles on research data that result from publicly funded research. The INFRA-ART Spectral Library is registered as a resource within the Open Science Cloud (EOSC) Portal and is among the services offered by the Romanian hub within E-RIHS (European Research Infrastructure for Heritage Science) DIGILAB.
Web-based open-access spectral databases relevant to conservation are nowadays a real necessity f... more Web-based open-access spectral databases relevant to conservation are nowadays a real necessity for heritage scientists and other heritage-related professionals that work with spectroscopic techniques. Fast and easy access to reliable high-quality databases is amplified by the fact that portable analytical techniques are becoming increasingly more used for in situ investigation of objects of art and archaeology. To address this need, within the frame of the postdoctoral project INFRA-ART, an open-access spectral library exclusively dedicated to art and cultural heritage materials has been developed. The INFRA-ART Spectral Library is an ongoing compilation of spectra that now contains over 1300 ATR-FTIR, Raman, and XRF spectra linked to over 680 known reference materials, and is currently part of the services offered by the Romanian hub within E-RIHS (European Research Infrastructure for Heritage Science) DIGILAB. This paper presents the key features of the INFRA-ART database, along some aspects regarding database accessibility, and upcoming developments.
ACM Journal on Computing and Cultural Heritage, 2023
Easily accessible characterization techniques such as X-ray fluorescence (XRF), Fourier Transform... more Easily accessible characterization techniques such as X-ray fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), or Raman spectroscopy, are at this moment the most commonly used analytical tools in heritage and conservation science. Materials identification in works of art is a fundamental step for understanding an object's history or an artist's technique. Comprehensive characterization and diagnosis of the various constituent materials in artworks can provide valuable information on the artist's working methods, as well as significant evidence for dating, provenance attribution, or forgery detection. The development of databases with high-quality data on the pure substances used as artists’ materials is of utmost importance for the identification and characterization of unknown samples. However, there are relatively few open access spectra libraries dedicated exclusively to the cultural heritage field. To address this need, within the frame of the postdoctoral project INFRA-ART, an open access spectral library of art-related materials has been developed. The database is an ongoing compilation of spectra that contains at this moment over 1,000 high-quality attenuated total reflection–FTIR, Raman, and XRF spectra associated with over 500 known reference materials. In this article, a summary of the database structure and design, functionality, and use is presented, in view of the dissemination of this new open access spectral library to the scientific community.
With the rapid scientific and technological changes that occur every day, a new kind of necessity... more With the rapid scientific and technological changes that occur every day, a new kind of necessity, real-time, rapid, and accurate detection methods, preferably also non- or minimally invasive and non-destructive, has emerged. One such method is laser-induced fluorescence spectroscopy (LIF), applied in various fields of activity in recent decades, ranging from industry and biochemistry to medicine and even heritage sciences. Fluorescence-based spectroscopic methods have all of the above-mentioned characteristics, and their functionality has been proven in many studies. Yet, they have not known great success as other molecular techniques. This paper is a short synthesis of the role of the laser-induced fluorescence spectroscopy technique in heritage sciences, the main applications in this field, along with its advantages and limitations. The article focuses on the most common types of lasers used, the merging of two or more methods into hybrid techniques, the enhancement of the analytical capabilities of LIF and post-processing methods, and also explores some future development possibilities of LIF.
Natural minerals and earths with coloring properties have been widely used as artistic pigments s... more Natural minerals and earths with coloring properties have been widely used as artistic pigments since prehistoric times. Despite being extensively studied, the complex chemistry of earth pigments is still unsatisfactory described with respect to their mineralogical and structural variability and origin. In this study, a large group of earth pigments from various geographical locations was investigated using easily accessible spectroscopic techniques and multivariate analysis with the aim to identify distinctive mineralogical and chemical characteristics of natural pigment sources. Portable X-ray fluorescence (p-XRF), Fourier transform infrared spectroscopy (FTIR) and fiber optic Raman spectroscopy were used for the elemental, molecular and structural characterization of the investigated pigments. Diagnostic spectral features and chemical patterns (fingerprints) were identified and discussed with respect to their geological sources. Due to the occurrence of similar accompanying minerals, it was observed that the differentiation of red and yellow ochers is more challenging compared to green, brown and black pigments. However, for some of the investigated pigments, the presence of certain accessory minerals and/or of certain chemical patterns can have diagnostic value. Principal component analysis (PCA) of the FTIR and XRF data matrices showed promising results in terms of geological attribution, highlighting a promising tool for provenance research. The results of the study demonstrate the potential benefits of this rapid and nondestructive approach for the characterization and differentiation of earth pigments with similar hues coming from different geological sources.
Often associated with acts of vandalism, graffiti can also be identified with the so-called stree... more Often associated with acts of vandalism, graffiti can also be identified with the so-called street art movement. Moreover, in the historical context of visual arts from the 20th and 21st century, graffiti spray paints feature among the materials employed in the work of representative artists such as Lucio Fontana, Richard Hamilton, Yves Klein, or David Alfaro Siqueiros. In this study, a large number of artist spray paints were analyzed by means of X-Ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FTIR), spectrophotometry, and Hyperspectral Imaging (HSI). The aim of the study was to provide a chemical characterization of the main organic and inorganic components present within the spray paint formulations by means of a complementary non-destructive approach. Titanium white, zinc white, bismuth vanadate yellow, ultramarine, strontium sulfide, iron, and copper oxides, along a series of pigments of the azo, phthalocyanine, and quinacridone classes could be identified. High amounts of barium sulfate as well as calcium-based extenders were also detected. FTIR analysis provided important information regarding the binder composition, mainly modified alkyd resins being identified. Additional information related to the existing chromophores as well as specific binder-pigments interactions could also be highlighted within the HSI data sets. Overall results provide new insights on the complex chemistry of this new range of materials, which could help future investigations carried on street art graffiti, contemporary murals, or mixed-media artworks.
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