Panel Paintings Research Articles

Laboratory X-ray powder micro-diffraction in the research of painted artworks

Painted artworks represent a significant group of cultural heritage artifacts, which are primarily admired because of their aesthetic quality. Nevertheless, the value of each particular painting depends also on what is known about it. Material investigation of paintings is one of the most reliable sources of information. Materials in painted artworks (i.e. panel, easel and miniature paintings, wall paintings, polychromed sculptures etc.) represent an extensive set of inorganic and organic phases, which are often present in complicated mixtures and exhibit characteristics reflecting their geological genesis (mineral pigments), manufacturing technology (artificial pigments), diverse biological nature (binders or dyes) or secondary changes (degradation or intentional later interventions). The analyses of paintings are often made challenging by the heterogeneous nature and minute size of micro-samples or, in some cases, even by the impossibility of sampling due to the preciousness, fragility or small dimensions of the artwork. This review demonstrates the successful implementation of laboratory X-ray powder micro-diffraction for material investigation of paintings, illustrating its efficiency for mineralogical analysis of (i) earth-based materials indicating the provenance of paintings, (ii) copper-based pigments pointing to their origin, and (iii) products of both salt corrosion and saponification enabling one to reveal the deterioration and probable original appearance of artworks.

Timber trade in 17th-century Europe: different wood sources for artworks of Flemish painters

The former Spanish Netherlands experienced a period of social, cultural and economic prosperity in the seventeenth century, with Antwerp as its most important commercial and artistic centre. The era’s vibrant art scene, once pivotal culturally, economically, and diplomatically, now offers invaluable insights for scientific studies on art, trade, and craftsmanship. In a study on 294 panel paintings by or related to two famous Flemish artists, Jacques Jordaens (1593–1678) and Anthony van Dyck (1599–1641), we applied classical art historical techniques, archival research, dendrochronology, and the study of panel maker’s and guild marks on the painting’s reverse to gain insights into the precise time of tree felling, the geographical provenance of the wood, and the panel makers patronised by the painters. The majority of the paintings (~ 80%), which were subjected to a dendrochronological analysis, could be dated and the results accorded well with the concomitant art historical assessment on authorship. Besides an active and well-known Baltic timber trade which provided over 71% of all the planks examined, straight-grained oak trees were also sourced from western Central Europe (20%). Interestingly, planks from the Baltic and the Ardennes region (France/Belgium) were used together in three different paintings, likely cut apart from larger panels. Employing a multidisciplinary approach to a comprehensive painting collection by individual painters provides not only a new tool to determine a painting’s date and authorship but also allows for a better understanding of the contemporary timber trade and associated craftsmanship.

Intervention Criteria in the Restoration of the Panel Painting Christ tied to the column from the Diocesan Museum of Sacred Art in Salamanca, Spain, which was attributed to Luis de Morales

El siguiente artículo tiene como objeto explicar el proceso de restauración llevado a cabo en el año 2021 de la pintura de tabla Cristo atado a la columna, obra inédita de Luis de Morales. Tras su hallazgo en la villa de Alba de Tormes (Salamanca, España), procedente probablemente de la iglesia de San Juan Bautista de la referida villa, esta obra ahora forma parte de la exposición permanente Misterio Admirable del Museo Diocesano de Arte Sacro de Salamanca, inaugurada en marzo de 2023, en el Palacio Episcopal de Salamanca. La intervención realizada de la pieza se destaca por la aplicación del método científico para su atribución, y durante todo el proceso de restauración, aunada con el sentido teológico que aporta al marco del siglo XVII y al significado iconológico. ___________ The following article explains the restoration process carried out during 2021 of the panel painting Christ Tied to the Column, an unprecedented work by Luis de Morales. After its discovery in the town of Alba de Tormes (Salamanca, Spain), possibly originating from the church of San Juan Bautista in the aforementioned town, the artwork has been included in the permanent exhibition named Misterio Admirable (Admirable Mystery) at the Museo Diocesano de Arte Sacro de Salamanca. Which was inaugurated in March 2023 in the Episcopal Palace of Salamanca. The intervention carried out in the piece stands out for the application of the scientific method for its attribution. The whole restoration process is combined with the theological sense that contributes to the 17th-century setting and the iconological meaning.

Linear Regression Algorithm Analysis for Predicting Electrical Panel Painting Quality

Linear Regression Algorithm Analysis for Predicting Electrical Panel Painting Quality

Indoor paint life cycle particle release: Safer-by-design products and the importance of choosing the right formula

In 2020, the European Commission published a regulation that states all producers of white paints containing titanium dioxide (TiO2) must provide a warning label on their products. Exposure during the production and application of products containing TiO2 can be harmful, and therefore these products must be labeled as “may cause cancer.” The paint industry is a major user of TiO2 pigment. This study focuses on pigment release from three TiO2-based paints and discusses the effect of paint formulation, more precisely the Pigment Volume Concentration (PVC), to predict TiO2 pigment release from the paints during a simulated use phase and at the end of life (EoL). The use phase considered mild abrasion of painted panels that simulated cleaning or touching. The EoL phase was studied using leaching tests simulating landfill disposal. TiO2 release during both activities was evident with a high discrepancy between the three paints. While dry rubbing was similar for all paints, activities involving water present a high release link to paint matrix degradation. The paint pigment volume concentration and the paint permeability determines the TiO2 release during wet rubbing and leaching. This work represents an attempt to identify the paint permeability as a matrix-related parameter to predict TiO2 release and a way to use of this parameter to develop safer products.

Exploring the Feasibility of Eu(TTA)3TPPO as Pigment for Fluorescent Paint

We outline the synthesis of rare earth hybrid organic β-diketonate Eu(TTA)3TPPO complex [Eu: Europium, TTA: Thenoyl Trifluoro Acetone, TPPO: Triphenylphosphine oxide] pigment to formulate luminous paints. Epoxy and urea formaldehyde resins were synthesized by catalytic homo polymerization and solution polymerization technique, respectively. The fluorescent pigment was synthesized at ambient temperature by solution technique, maintaining the stoichiometric ratio at pH 7. Nextly, fluorescent paint was developed on glass substrate with epoxy (E) and urea formaldehyde (UF) resins and toluene as solvent with thickness 0.1 mm, respectively. Photoluminescence (PL) spectra and photometric assessment of the complex were carried out to probe its photophysical parameters. The excitation spectra of the synthesized complex depicts a wide-ranging excitation peak at 466 nm with a wide shoulder at 538 nm, while emission spectra discloses an intense peak, recorded at 617 nm which portrays colour in the reddish-orange region of the visible spectrum. The paint compositions were checked for tack-free, hard dry, adhesion, water, salt, alkali and acid spray test to study their resistance against distinct surroundings. The painted panels also portrayed reddish orange emission at a unique wavelength of 617 nm. Amid all the paint compositions, the intensity of the painted panel with urea formaldehyde as a binder was found to be maximum, followed by the painted panel with epoxy as the binder. Photometric evaluation revealed reddish-orange emission from pure pigment as well as painted panels, which portrayed in the visible spectrum. This proposes a way to develop fluorescent paints that find applications in several areas such as flexible displays, glow-in-dark road paints, OLED devices, automotive rare lighting, fluorescent sensors, aircraft cabin and floor lighting, architectural and interior decorations and many more.

MA-XRF datasets analysis based on convolutional neural network: A case study on religious panel paintings

Macroscopic X-ray fluorescence (MA-XRF) datasets are analyzed using Artificial Neural Networks. Specifically, Convolutional Neural Networks (CNNs) are trained by coupling the spectra acquired during the MA-XRF scan of two religious panel paintings (“icons”) with the associated Ground-Truth counts per characteristic transition line, as they are extracted by X-ray fluorescence fundamental parameters analysis. In total, twenty thousand XRF spectra were used for the CNN training. The trained neural networks were applied to analyze millions of MA-XRF spectra acquired during the scan of religious painting panels by computing the counts per pixel of X-ray characteristic transition lines and creating the elemental transition maps. Comparison of the CNN extracted results to the Ground-Truth (GT) shows remarkable agreement. The successful MA-XRF datasets analysis applying the CNN method paves an analytical path to the direction of the auto-identification of spectral lines, offering the means for the non-experienced XRF analyst to provide a state-of-the-art analysis and supporting the experienced user not to overlook hardly resolved transition lines.

Icons of the Nursing Virgin in Fifteenth-Century Ethiopia

The oldest known extant Ethiopian panel painting is Fəre Ṣəyon’s Nursing Virgin with Saints Stephen, Peter, and Paul (ca. 1434–68), preserved at the Monastery of Daga Ǝsṭifanos. As I argue, this novel subject matter for Ethiopian religious culture emerged in light of Emperor Zärˀa Yaˁqob’s introduction of the cult of the Virgin Mary in 1441 and Giyorgis of Sägla’s writings, which drew upon translations of early medieval Egyptian and late ancient Syrian texts. Numerous adaptations of Fəre Ṣəyon’s panel prove its long-lasting impact in fifteenth century sacred art as an original and influential Ethiopian artwork in its own right.

Development of craquelure patterns in paintings on panels

Panel paintings are multi-layer structures composed of humidity-sensitive materials. Preventing or limiting stresses in these structures, generated by the loss or gain of moisture, requires an understanding of the relevant processes and risks. A three-dimensional elastic model of a panel painting was used to analyse surface stresses and understand how crack patterns are developed in the two-layer structure of the pictorial layer—the gesso and the paints. Two historically important paint types were considered—egg tempera and oil paints, laid on a gesso produced following historical procedures. Two scenarios of stress development were analysed: permanent cumulative drying shrinkage of paints or gesso, owing to gradual loss of water or evolution of the molecular composition of the binders, and moisture-induced cyclic swelling of the wood substrate. Ratios of distances between cracks in the tangential and longitudinal directions of a wood panel to the layer thickness were estimated for increasing magnitudes of materials’ dimensional change in the two scenarios. The critical values of the ratios for which stress in the midpoint between the cracks dropped below the value inducing strain at break in the materials and saturation of the crack patterns occurred, was approximately 3–4 or 5–6 for the paints and the gesso, respectively. The critical distance normalized to the gesso thickness between cracks parallel to the wood grain induced by cyclic swelling of the wood substrate due to relative humidity variation in the range of 50–70% was 6. The study demonstrated that crack spacings in the fully developed crack systems remain sensitive only to the thicknesses of paint or gesso layers which, therefore, can be derived from the crack pattern geometry. Existing flaws in gesso were found not to increase the risk of new crack development.

Hygrothermal ageing of dry gelatine adhesive films: Microstructure-property relationships

Gelatine adhesives, also known as animal glues, are collagen-based water-soluble biopolymers derived from vertebrate connective tissues. One of the various fields in which gelatine adhesives are widely used is the conservation of cultural heritage such as decorated furniture and panel paintings. It is observed that, with time, the failure in these objects often occurs along the adhesive bondlines. Given the moisture and temperature sensitivity of these adhesives, obtaining knowledge of their long-term behaviour, when exposed to climate variations, is pivotal. Here, the influence of hygrothermal ageing (exposure to a combination of elevated temperature and relative humidity (RH) cycling) on the microstructure and macroscopic properties of four different types of gelatine adhesives is investigated. These adhesives were selected from different animal origins namely bovine, rabbit, and fish with different Bloom strengths. It was observed that ageing cycles interfere with the most critical structural feature of protein chains namely triple helices. A clear decay in triple helix content at the micro-scale, determined by Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD) techniques, was observed which had implications on the macroscopic properties of these adhesives such as reduction of strain to failure and toughness (strain energy density to failure). The rate of decay in properties was revealed to be the highest in the adhesives with the lowest triple helix content. This study provides a scientific view of microstructure-property relationships in gelatinous adhesives as a function of environmental ageing, and stipulates the underlying mechanism of the degradation of mechanical properties as the loss of structural triple helices, regardless of the animal origin.

Exploring the inner hygro-mechanical behaviour of historical panel paintings: a novel approach using digital twins

Wooden Panel Paintings (WPPs) stand as invaluable cultural artefacts from the past. These works present an intriguing challenge in understanding their complex mechanical behaviour and ensuring their long-term preservation. The present study assumes as founding paradigm the unicity of each WPP, in terms of its material composition, historical background, physical dimensions, and the specific environmental conditions it has been subjected to over time, and their complex behaviour, which requires the knowledge of both mechanical and materials specificity. These characteristics need to be considered, and studied in-depth for each individual WPP, particularly if the aim is to develop a comprehensive understanding of its individual mechanical behaviour. The study provides new computational models calibrated to reproduce the physical and mechanical behaviour of artworks and acting as their 'digital twins'. The models developed contribute significantly to the understanding of the mechanics of these artworks, including the impact of environmental thermo-hygrometric fluctuations and the role of structural elements such as crossbeams. The results, corroborated by experimental analyses, indicate that environmental variations, both short and long term, exert specific and quantifiable effects on the WPPs, and that the presence of crossbeams significantly influences the distribution of stresses within the panel, particularly affecting the pictorial layers that are often the most susceptible to damage. In this context the generated digital twins serve as an invaluable tool, offering the potential to simulate various risk scenarios or to evaluate the effectiveness of engineered conservation interventions on the WPPs.

Mechanical and moisture-related properties of selected dried tempera paints

Mechanical properties—modulus of elasticity and strain at break, water vapour sorption, and hygroscopic expansion of selected egg tempera and distemper paints were determined as a function of relative humidity (RH) filling in this way a critical gap in the knowledge required for the analysis of fracturing processes in paintings. The experimental work was made possible by the preparation of several tempera paints, mimicking the historical materials, in the form of large specimens. Lead white, azurite, and yellow ochre were selected as pigments, and egg yolk and rabbit skin glue as binding media. The water vapour sorption and the moisture-related swelling of the paints were dominated by the proteinaceous components of the binders. The linear hygroscopic expansion coefficient of the dried egg yolk binder was approximately 1 × 10−4 per 1% RH, several times less than the coefficient of the collagen glue (4 × 10−4 per 1% RH). The moduli of elasticity of egg tempera paints at the RH mid-range were comparable to the moduli of aged oil paints, whilst the modulus of elasticity of the distemper paint was close to values measured for animal glue-based grounds. The paints experienced the transition from brittle to ductile states on increasing RH. The egg tempera paints were found to be more brittle than the distemper paint, gessoes, and, generally, aged oil paints. The observations modify a frequently used laminar model of panel paintings in which the mismatch in the response of glue-based ground layer and wood substrate to variations in RH has been identified as the worst-case condition for the fracturing of the entire pictorial layer. This study demonstrated that tempera could be more brittle than the ground layer and in consequence more vulnerable to cracking.

The detection of incamottatura through radiography: investigations on real cases and panel painting mock-ups

The historical techniques of panel painting manufacturing involve the preparation of boards to be used as painting support. The high affinity of wood for water can cause dimensional variations, deformations, and internal tensions. The application of a canvas over the boards, besides the choice and treatment of wood, is useful to minimize and guarantee the stability and preservation of the painting over time. The detection of the fabric is ensured with different imaging techniques, such as macro photography and radiography. The latter is mainly used to obtain information about the characteristics of the wood, the number of boards, the assembly system, and for the evaluation of the conservation state. The main advantage is the non-invasiveness of the analysis, which is a fast, simple, and widespread method. The limitations are related to different factors, such as the capacity of the materials to absorb the radiation. Despite canvas has a low radiopacity, in several cases it was possible its identification in the radiograph. This is important to investigate the technique of the artists. In our laboratory, we analyzed different panel paintings and while in some cases the fabric is easily detectable, in others it's not visible. Different variables can limit the observation of the canvas. This study is aimed at the comprehension of how acquisition parameters and painting characteristics can affect the detection of incamottatura through radiography.

Rediscovering the Painting Technique of the 15th Century Panel Painting Depicting the Coronation of the Virgin by Michele di Matteo

The study concerned a diagnostic spectroscopic campaign carried out on the panel painting depicting the Coronation of the Virgin (first half of the 15th century) by the late-Gothic Italian painter Michele di Matteo. The main aims were the identification of the original painting materials and the characterization of the painter’s artistic technique. A combined approach based on non- and micro-invasive techniques was employed. Visible and ultraviolet-induced fluorescence photography was used to select the areas of interest for spectroscopic analyses; X-ray radiography assessed the state of conservation of the support, while X-ray fluorescence and external reflection Fourier transform infrared spectroscopies allowed the chemical identification of pigments, binders, and varnishes. Attenuated total reflection infrared spectroscopy, optical microscopy, and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy were used to visualize and characterize the materials in the pictorial layers. The results highlighted the presence of pigments, possibly applied with an egg binder, consistent with the period of the production of the painting, as well as modern pigments used during subsequent restorations: an imprimitura with lead white and a gypsum-based ground layer. Concerning the gilding, the guazzo technique was confirmed by identifying a red bolo substrate and gold leaf.

Интеграция многофигурных повествовательных сцен и структурные трансформации в итальянском алтарном полиптихе XIV века

Painted polyptych altarpieces appeared on high altars in late Duecento in the churches of mendicant orders. They were characterized by a special manner of organizing visual material by juxtaposing single half-figures with each other and arranging them in rows and columns, allowing no room for narrative elements, widely used at that time in panel painting. Such narrative-free character of main altarpieces would be preserved throughout the whole period of their popularity. However, polyptychs created in late Trecento integrated narrative scenes and even entire cycles into the structure of the altarpieces, which required new approaches to composition and to the use of pictorial space. The article examines the role of narrative content in altarpieces of late Trecento and discusses the origins and development of this new style.

Michelangelo's Left-Hand Man: Minding the Gap in Sebastiano del Piombo's Pietà

Abstract: This article considers the vitality of the left hand of Christ in a monumental Pieta panel painting by the Italian Renaissance artist Sebastiano del Piombo (bom Sebastiano Luciani, ca. 1485–1547) and a vital link between this hand and the left hand of Adam in the Creation scene on the Sistine Chapel ceiling by Michelangelo (1475–1564). Sebastiano's work was made in the central Italian city of Viterbo around 1512 to 1516, and shows a seated Virgin Mary grieving the death of Christ, her son, whose body lies on the ground in front of her. The article focuses on the representation of Christ's body, identifies a gap between the fingers of Christ's hand and his thigh underneath, and explores this gap's significance as a sign of life. It first reveals a close and as yet not remarked upon connection between the hands in the Pieta and the Sistine Chapel. Through consideration of a series of sketches and drawings that highlight the close working relationship between Sebastiano and Michelangelo during and around the years of the Pieta'' s production, the likelihood that the left hand of Christ in Viterbo was designed by Michelangelo is confirmed. The hand was probably sent to Sebastiano as a drawing from which he worked a cartoon. By examining the iconography of the painting and its associations to Adam's spirited hand in Michelangelo's Creation alongside biblical passages and a popular religious text, the Meditations , the article argues that the restless left hand of Christ in Sebastiano's Viterbo Pieta is a symbol of Christ's Resurrection.

Green synthesis of Eucalyptus globulus zinc nanoparticles and its use in antimicrobial insect repellent paint formulation in bulk industrial production

Mitigating climate change can be achieved by opting for sustainable, plant-based materials instead of relying on hazardous chemicals that come with various side effects. Various natural plant extracts find widespread application in synthesizing insect-repellent coatings, particularly in industries such as paint manufacturing. The increasing demand for these coatings has led us to find out the effects of different plant extracts for the efficient preparation of paints with more advanced impacts and low cost. For this purpose, zinc nanoparticles of Eucalyptus globulus L. and its extracts were used in this study due to their remarkable biocidal and antimicrobial activities. The extract was prepared by the process of oven-drying and heating followed by their filtration. Then, they were subjected to different phytochemical tests that were performed in which plant material did not contain flavonoids and glycol. The comparison of the size of nanoparticles was visible during the weighing which was found to be 4.451 mg. Advanced characterization techniques like FTIR, UV visible spectroscopy, and particle size analysis were adopted for the analysis of nanoparticles of plant extract. The FTIR analysis of the plant material was reported to lie in the range of 1000–1800 cm−1. On the other hand, the results of UV visible spectroscopy of nanoparticles of plant extract showed absorption peaks around 300 nm. The produced material was integrated into paint formulations to impart insect-repellent and antibacterial characteristics. Painted panels exhibited notable antibacterial efficacy, presenting an inhibition zone of 0.7 cm for Escherichia coli and 0.3 cm for Staphylococcus aureus when utilizing biocide. Plant nanoparticles yielded inhibition zones of 1 and 1.2, while aqueous extract resulted in zones of 0.2 and 0.5, respectively. A thorough evaluation of the paint's color attributes, including ΔL, Δa, Δb, and ΔE, indicated noteworthy differences. The CMC ΔE values from the trials exceeded 1, indicating a substantial change in shade. The batches of paints containing E. globulus extracts and nanoparticles were found to be lighter in color specifically green and yellow colors. Their antimicrobial and insect repellant activity was tested using the mosquitos of Aedes aegypti with an age of 4–5 weeks, revealing that formulations with plant extracts exhibited a 61 % effective period, greater than the 7 % observed in non-biocidal formulations. The paint responded best towards these mosquitoes in terms of repellency and the ultimate target of this study was achieved.

Baroque Iconostases of Eastern Podillya: the Main Structural Types

The iconostases of Eastern Podillya remain a little-known phenomenon that has been ignored by researchers of sacred art, with the exception of Oleh Sydor. The purpose of the article is to analyze and systematize the Eastern Podillya Baroque iconostases (based on the material of Vinnytsia region) by the types of constructions. The analysis of the preserved sacral ensembles and photographs of the lost ones gave reasons to identify four main groups of architectural structures. The monuments of the first group had a strictly horizontal layout of tiers, and the central vertical division was accentuated by larger elements and richer wooden carvings. In the second group, a gradual scale increase toward the centre is observed, starting, as a rule, from the Festival tier. For this purpose several methods were used: cornice bending above the deacon’s doors; placing above the nave row (between the deacon’s doors) an additional tier, mostly of Pentecost Sunday, or a decorative carved or painted panel, etc. Characteristic of the next type is the arched arrangement of the icons of the upper tiers of the middle part, starting from the Festival row. Finally, the fourth group comprises iconostases with creases symmetrical to the central axis, with the tiers in such ensembles being arranged on the same level or in stepwise order. The iconostases of the first three types had a straight line in the plan (alternatively, the side wings were wrapped around the log cabin walls), while the monuments of the fourth type had a broken (zigzag) line. Considering the limited amount of visual material involved, further research prospects depend on the discovery of new sources (iconostases, photographs or sketches), the study of which will allow verifying the conclusions made.

3D multi-modal point clouds data fusion for metrological analysis and restoration assessment of a panel painting

This paper reports the results obtained from the workflow designed for the 3D survey of a Renaissance panel painting using close-range photogrammetry and conoscopic laser microprofilometry, before and after its restoration. The artwork under examination is the central panel of a Renaissance polyptych realized by a late Gothic painter active in central Italy in the late 15th century. This painting has had a rather troubled conservation history following numerous adverse events that have severely damaged it structurally. In preparation for restoration work, the fusion of point cloud data derived from active and passive sensors served to create a single multi-resolution model on which to conduct advanced metrological analyses for multi-temporal monitoring of the changes undergone by the panel painting during and after structural restoration.

Panel Paintings Inspection Analysis Using Active Thermography in the Mid-Wave and Long-Wave Infrared Region

Active thermography was used for characterisation of multi-layered paintings panel structures and analysis of defects caused by aging and environmental effects. Pulsed Thermography setup was applied to provide and inspect a dynamic thermal response, which was recorded by mid- and long wavelength infrared TELOPS cameras. Control, synchronization and data analyses were provided by Professional software (DisplayImg 7). Active thermography was demonstrated as being appropriate for characterization of various defects on painting layers and detection of under-drawings, pentimenti and canvas. Such multispectral approach provided simultaneous complementary information on the specimen under inspection.