Macro X-ray Fluorescence Scanning Research Articles

Tricks of the Shade: Preservation of Chemically Developed Shading Papers Based on DuoShade Samples

ABSTRACT From the late 1920s through the early 2000s, artists sometimes utilized chemically developed shading papers, or “chemigraphic” papers, to add dimensional effects to their drawings. These papers were precoated with patterns that were selectively revealed by applying a liquid developer. Drawings on these types of papers often show signs of deterioration, such as discoloration and fading of the developed patterns and staining of the paper support in areas where the developer was applied. This study investigates samples made from Grafix DuoShade chemigraphic papers and developers manufactured in the 1990s. These samples were analyzed to better understand their chemical makeup, deterioration, and preservation needs. The samples were characterized using macro X-ray fluorescence scanning and complementary spectroscopic techniques. To determine optimal storage environments, samples were artificially aged in different storage enclosures and colorimetry was used to compare the artificially aged samples to unaged controls. To determine optimal display environments, the light sensitivity of the samples before and after artificial aging was measured using microfadeometry. Based on the results, preservation recommendations for handling, storage, and display are provided.

Naples Yellow Revisited: Insights into Trades and Use in 17th-Century Sicily from the Macro X-ray Fluorescence Scanning of Matthias Stomer’s ‘The Mocking of Christ’

In a recent non-destructive analytical campaign at Museo Civico, Castello Ursino, in Catania, Italy, several paintings in the permanent collection were investigated by MA-XRF scanning, with a special focus on Matthias Stomer’s production. On one depiction of the Mocking of Christ (ca. 1640) donated to the municipality of Catania by G.B. Finocchiaro in 1826, the analysis documented the use of Naples yellow. Sb with Pb was detected in yellow areas of the Mocking of Christ, but not in his work Tobias healing his father. This finding possibly suggested an early use of lead antimonate yellow in South Italy, although it is generally accepted that this pigment was introduced in painting in the eighteenth century. Further details on his technique and later conservation treatments are provided, as well as literary comparisons with the artistic production during the same period, in Sicily and elsewhere. A systematic study of Stomer’s works, for example examining paintings produced while he was in Naples or Rome, might determine whether this material choice depended on local availability. Overall, it would shed light on his technique, as well as on the history of Naples yellow in southern Italy and beyond, before this pigment became so popular in the eighteenth century.

Tracing the history of past treatments: A multi-analytical study of a 16th-century panel painting copy after Raphael

A multi-analytical investigation and ad hoc sampling method designed to support the conservation treatment of a 16th-century panel painting are described in this work.The painting, titled Madonna of the Tent and owned by the Musei Reali Torino (Turin, Italy), had been historically attributed to Raffaello Sanzio and subsequently identified as a copy after the Master – the original version of which is displayed at the Alte Pinakothek in Munich (Germany). The conservation treatment was recently carried out at Centro per la Conservazione ed il Restauro dei Beni Culturali “La Venaria Reale” (CCR), located in Venaria Reale (Turin, Italy). The work was particularly opaque and yellowed, suggesting the presence of different overlaying varnishes and, likely, overpainting.The scientific study of this work had two main aims: knowing the exact number and composition of the overlaying varnishes to select the best cleaning solution, and detecting the possible presence of overpainting, over the original stratigraphy.Coupling macro X-ray fluorescence scanning (MA-XRF), hypercolorimetric multispectral imaging (HMI), and UV–vis–NIR fiber optic reflectance spectroscopy (FORS) allowed for general mapping and characterization of color paints and pigments. Observing and analyzing some cross sections with an optical microscope under Vis and UV light and SEM/EDS was essential for understanding the stratigraphy. An ad hoc sampling method and further micro-invasive analyses were required for an accurate study of the chemical composition of the varnishes and their position in the stratigraphy. Especially the image of a cross section under UV light was a guide to selectively remove the scrapings for Fourier transform infrared spectroscopy (FTIR) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) analyses; based on perceptible differences in UV-induced luminescence (UVL) of the layers, sampling of the varnishes was carried out, layer by layer, under a UV lamp.This work describes the complex process necessary to answer crucial questions in the conservation field. The adopted protocol exploited the full ability and complementarity of each imaging and spot technique used. The outcomes and methodological approach enabled us to trace the history of the past treatments and support the recent conservation treatment of the painting.

Probing creation process of paintings from Tarsila do Amaral (1886–1973) by MA-XRF and differential X-ray attenuation

Three artworks from Brazilian painter Tarsila do Amaral (1886–1973), “Manteau Rouge” (1923), “Vendedor de Frutas” (1925), and “Urutu” (1928), from different creative phases of the artist, were analyzed by macro X-ray fluorescence scanning (MA-XRF) technique. Based on the obtained elemental maps, it was possible to deduce the pigments employed by Tarsila during her different artistic phases. To investigate the ground applied in the paintings, XRF spectra were simulated with Zinc White and Lead White pigments in two categories: pure pigments, and another as ground. These simulated results were compared with experimental XRF data, allowing the discussion of the presence of Pb and Zn pigments in different layers of the paintings. From elemental maps, it was possible to observe repaintings in the “Manteau Rouge” and “Vendedor de Frutas”. Based on the results, it is possible to conclude that the painter utilized the same pigments consistently throughout her artistic phases, while exhibiting changes in her painting style.

The Unexpected Discovery of Syngenite on Margarito d’Arezzo’s The Virgin and Child Enthroned, with Scenes of the Nativity and the Lives of the Saints (Probably 1263–4) and Its Possible Use as a Yellow Lake Substrate

The oldest painting in the National Gallery collection, The Virgin and Child Enthroned by Margarito d’Arezzo (NG564), dated to about 1263–4, depicts the Virgin and Child in a mandorla, surrounded by scenes of the Nativity and lives of the saints, set within red and decorative black borders, against a gilded background. The materials and technique were investigated using a combination of non-invasive techniques, such as Fibre Optic Reflectance Spectroscopy (FORS) and macro X-ray fluorescence scanning (MA-XRF), and the analysis of a small number of paint samples using energy dispersive X-ray analysis in the scanning electron microscope (SEM-EDS), High-Performance Liquid Chromatography (HPLC), Attenuated Total Reflectance—Fourier transform infrared spectroscopy (ATR-FTIR) and micro X-ray Diffraction (micro-XRD). The results provided evidence for the use of a number of organic colourants, with both indigo and red lake pigments identified. The finding of an unusual compound, syngenite (K2Ca(SO4)2·H2O), is here postulated as a potential substrate for an organic yellow lake pigment. In addition, reference pigments were prepared to explore this hypothesis. Although documentary evidence confirms that yellow lakes were being produced from an early date, there is very little direct evidence for their use in 13th-century panel paintings.

Mapping with Macro X-ray Fluorescence Scanning of Raffaello’s Portrait of Leo X

Raffaello is renowned as one of the Old Renaissance Masters and his paintings and painting technique are famous for the details and naturality of the characters. Raffaello is famous in particular for the then-new technique of oil painting, which he mastered and perfected. On the occasion of the 500th anniversary of the death of Raffaello (2020), there was a large exhibition at the Scuderie del Quirinale in Rome, where many paintings and drawings by the Old Master were on show. One of these paintings was the portrait of Leo X with two cardinals belonging to the collection of the Uffizi galleries in Florence. Before going to Rome, the painting underwent conservation treatments at the Opificio delle Pietre Dure, where a comprehensive diagnostic campaign was carried out with the aim of understanding the painting materials and technique of the Old Master. In this paper, the results of macro X-ray fluorescence (MA-XRF) analysis, carried out exploiting the instrument developed by INFN-CHNet, are shown. Among the results, “bismuth black” and the likely use of glass powders in lakes are discussed.

Deconstructing the Creation of Daguerre’s dessins-fumées: A Photographic Process or Just Smoke and Mirrors?

ABSTRACT In the years before the public announcement of the daguerreotype process in 1839, Louis-Jacques-Mandé Daguerre and others experimented with variations on photographic processes, including a heretofore mysterious process used to create a group of objects known as dessins-fumées (or smoke drawings). Exacting in style and miniature in scale, each depicts one of a limited number of architectural motifs in black media. While compositions are repeated within the small set of known dessins-fumées, variations in superficial details and shading are observed between “copies.” The J. Paul Getty Museum has two of these rare objects, Moorish Arch and Courtyard of a Gothic Castle. The black materials used by Daguerre were characterized with non-invasive analytical methods, including digital microscopy, macro x-ray fluorescence scanning, Fourier-transform infrared spectroscopy, and Raman micro-spectroscopy; mockups were created to assess their potential methods of application. This research revealed that the Getty dessins-fumées are drawings and not produced by photographic or printmaking techniques. This study also characterizes the materials used to create the drawings and confirm the order in which they were applied. They are discussed with respect to how they address the uncertainty surrounding the development of photographic processes by Daguerre and others in the 1820s and 1830s.

Dutch or Iranian? Technical study of a seventeenth-century painting on paper from Gesina Ter Bosch\u2019s scrapbook

A scrapbook compiled between 1660 and 1687 by Gesina ter Borch (1631–1690), a female artist from the small town of Zwolle in the Netherlands, contains an intriguing painting on paper of a full-length portrait of a young Iranian. Although the figure wears the attributes in vogue at the Safavid court of Isfahan, certain elements seem rather incongruous and peculiar. The general composition appears static and rigid, an impression reinforced by an unusual black painted background. Stylistic differences within the painting were also observed, hinting at alterations to the original painting. To investigate the history of the painting and to reconstruct the original composition and identify the later additions, perhaps made by Gesina herself, the painting was examined with different imaging and analytic techniques available at the Conservation and Science Department of the Rijksmuseum. This allowed the research team to discriminate between pigments used for the original composition and pigments used to conceal damaged areas of the painting and added pictorial elements. After interpreting scientific results, as well as historical findings, it was possible to shed light on the use of specific pigments, namely lead white and smalt, and on the possible misinterpretation of some details, such as the cup held by the young man. The results of macro X-ray fluorescence scanning (MA-XRF) and lead isotope analysis, viewed in the light of information about the economic and cultural exchanges between Iran and the Netherlands in the seventeenth century, fed new theories about the origin and history of this painting. The painting, originally made in Iran in the style of Riza Abbasi, the head of the Emperor Shah Abbas’ library, ended up in Gesina ter Borch's workshop and may have been ‘restored’ by the artist to improve its condition and to match her tastes.

An applied complementary use of macro X-ray fluorescence scanning and multi-light reflectance imaging to study Medieval Illuminated Manuscripts. The Rijmbijbel of Jacob van Maerlant

The colorful images in medieval manuscripts have striking characteristics that need meticulous approaches during art technical research in situ, as no sampling is permitted. Visual inspections and images with the microscope can reveal details about techniques and layers of the miniature. In this experimental research we applied two complementary techniques to reveal the pigments the artists used to create the folios of a famous Flemish illuminated manuscript, the Rijmbijbel of Jacob van Maerlant (13th century, Bruges). This essay emphasizes on the combined possibilities and advantages of two different approaches. It focuses on exploring the same illuminations with MA-XRF analyses in a lab environment and the multi-light reflectance technique (MLR) of the Multi-Spectral Microdome (MS MicroD) in situ. Through comparing and combining MA-XRF analysis with the MS MicroD datasets reference data, the ink and paint layer compositions could be characterized. The essay illustrates the capabilities of both techniques to obtain new insights in the material composition of the paint of a well-described and examined artefact. The genuine 13th century materials and the 19th century retouching could be visualized, differentiated and determined. Finally, the added value of the combination of the two examination methods is evaluated for art technical research on illuminated manuscripts.

In situ macro X-ray fluorescence (MA-XRF) scanning as a non-invasive tool to probe for subsurface modifications in paintings by P.P. Rubens

Within the last decade, the established synchrotron- and laboratory-based micro-XRF scanning technology inspired the development of mobile instruments that allow performing in situ experiments on paintings on a macro scale. Since the development of the first mobile scanner at the start of this decade, this chemical imaging technique has brought new insights with respect to several iconic paintings, especially in cases when standard imaging techniques such as X-Ray Radiography (XRR) or Infrared Reflectography (IRR) yielded ambiguous results. The ability of scanning MA-XRF to visualise the distribution of elements detected at and below the paint surface renders this spectrometric method particularly helpful for studying painting techniques and revealing materials that remain hidden below the paint surface. The latter aspect is especially relevant for the technical study of works by Pieter Paul Rubens (1577–1640) as this highly productive seventeenth century master is particularly renowned for the continuous application of modifications during (and even after) the entire course of the creative process. In this work, the added value of MA-XRF scanning experiments for visualising these subsurface features is exemplified by interpreting the chemical images obtained on three of Rubens' key works. Special attention is given to three types of adjustments that are particularly relevant for the technical study of Rubens' oeuvre: (1) compositional changes (‘pentimenti’), exemplified by results obtained on The Portrait of Hélène Fourment (ca. 1638), (2) extensions to the support (‘Anstückungen’), illustrated by imaging experiments performed on the Venus Frigida (1614) and (3) Rubens' intriguing halos around flesh tones, as found amongst others in The Incredulity of Saint Thomas (1613). The ensuing insights in the paint stratigraphy and the underlying supporting structure illustrate the potential of MA-XRF scanning for the non-invasive, comparative study of Rubens' oeuvre. The results do not only augment the understanding of the complex genesis of Rubens' works of art and his efficient painting technique, but prove valuable during conservation treatments as well, as addressed in this paper.

Macro X-ray fluorescence scanning (MA-XRF) as tool in the authentication of paintings

Scanning macro X-ray fluorescence (MA-XRF) was evaluated as a means for the non-invasive study of two paintings to investigate their authenticity. The first painting, a still-life attributed to the 17th century Spanish painter Francisco de Zurbarán, was analysed both with point XRF analyses and MA-XRF. MA-XRF analyses facilitated the interpretation of the results, revealed a hidden painting and gave a clear answer on the question of authenticity. The second painting, attributed to the workshop or school of Pieter Paul Rubens, was investigated by MA-XRF alone. This revealed a hidden stamp of a canvas manufactory, which situated the painting a few hundred years later than originally supposed. In this last case MA-XRF results were supported by X-radiography and infrared reflectography (IRR). A brief comparison was made between MA-XRF and these traditional scientific imaging techniques, which were not able to detect the stamp. Moreover, it is suggested that in certain cases where for budgetary reasons X-radiographs cannot be made, MA-XRF images can sometimes suffice.

Jan Davidsz. de Heem (1606\u20131684): a technical examination of fruit and flower still lifes combining MA-XRF scanning, cross-section analysis and technical historical sources

This article discusses the technical examination of five flower and fruit still life paintings by the seventeenth century artist Jan Davidsz. de Heem (1606–1684). The painter is known for his meticulously composed and finely detailed still life paintings and is a master in imitating the surface textures of various fruits, flowers, and objects. Macro X-ray fluorescence (MA-XRF) scanning experiments were supplemented with a study of paint cross-sections and contemporary art technical sources with the aim of reconstructing the complex build-up of the overall lay-in of the composition and individual subjects. MA-XRF provided information on the distribution of key chemical elements present in painting materials and made it possible to recapture evidence of the different phases in the artist’s working methods: from the application of the ground layers, to De Heem’s characteristic oval-shaped underpaintings, and finally, the superposition of multiple paint layers in the working up of the paintings. SEM–EDX analysis of a limited number of paint cross-sections complemented the chemical images with local and layer-specific information on the microscale, providing more accuracy on the layer sequence and enabling the study of elements with a low atomic number for which the non-invasive technique is less sensitive. The results from this technical examination were in addition compared with recipes and paint instructions, to obtain a better understanding of the relation between the general practice and actual painting technique of Jan Davidsz. de Heem. Ultimately, this combined approach uncovered new information on De Heem’s artistic practice and demonstrated the complementarity of the methods.

The young Van Dyck\u2019s fingerprint: a technical approach to assess the authenticity of a disputed painting

The painting Saint Jerome, part of the collection of the Maagdenhuis Museum (Antwerp, Belgium), is attributed to the young Anthony van Dyck (1613–1621) with reservations. The painting displays remarkable compositional and iconographic similarities with two early Van Dyck works (1618–1620) now in Museum Boijmans van Beuningen (Rotterdam) and Nationalmuseum (Stockholm). Despite these similarities, previous art historical research did not result in a clear attribution to this master. In this study, the work’s authenticity as a young Van Dyck painting was assessed from a technical perspective by employing a twofold approach. First, technical information on Van Dyck’s materials and techniques, here identified as his fingerprint, were defined based on a literature review. Second, the materials and techniques of the questioned Saint Jerome painting were characterized by using complementary imaging techniques: infrared reflectography, X-ray radiography and macro X-ray fluorescence scanning. The insights from this non-invasive research were supplemented with analysis of a limited number of cross-sections by means of field emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The results demonstrated that the questioned painting’s materials and techniques deviate from Van Dyck’s fingerprint, thus making the authorship of this master very unlikely.

Macro X-ray fluorescence (MA-XRF) scanning of illuminated manuscript fragments: potentialities and challenges

Macro X-ray fluorescence scanning (MA-XRF) is gradually becoming an established technique for the non-invasive analytical investigation of painted surfaces. This paper discusses some of the benefits and limitations of employing MA-XRF for the study of manuscript illuminations. Art historical research on this type of artefacts that is based on scientific measurements is often limited by the fact that usually no sampling can take place. Hence there is a need for non-invasive analytical tools that make it possible to conduct systematic investigations. As a representative example of this type of objects, a 15th century Italian manuscript fragment from the collection of the Fitzwilliam Museum in Cambridge (UK) is investigated. The aims of the study were to gain insight into the materials and techniques employed by Renaissance illuminators and to help answer specific questions regarding the fragment’s authorship and geographic origin. The complementarity and advantages of MA-XRF mapping versus site-specific analyses are discussed. For this purpose, MA-XRF data are evaluated and compared with the results of other analytical techniques. The interpretation of the elemental maps is discussed along with the challenges faced during the analysis.

Chemical imaging of stained-glass windows by means of macro X-ray fluorescence (MA-XRF) scanning

Since the recent development of a mobile setup, MA-XRF scanning proved a valuable tool for the non-invasive, technical study of paintings. In this work, the applicability of MA-XRF scanning for investigating stained-glass windows inside a conservation studio is assessed by analysis of a high-profile, well-studied late-mediaeval panel. Although accurate quantification of components is not feasible with this analytical imaging technique, plotting the detected intensities of K versus Ca in a scatter plot allowed distinguishing glass fragments of different compositional types within the same panel. In particular, clusters in the Ca/K correlation plot revealed the presence of two subtypes of potash glass and three subtypes of high lime low alkali glass. MA-XRF results proved consistent with previous quantitative SEM-EDX analysis on two samples and analytical-based theories on glass production in the Low Countries formulated in literature. A bi-plot of the intensities of the more energetic Rb–K versus Sr–K emission lines yielded a similar glass type differentiation and is here presented as suitable alternative in case the Ca/K signal ratio is affected by superimposed weathering crusts. Apart from identification of the chromophores responsible for the green, blue and red glass colors, contrasting the associated elemental distribution maps obtained on the exterior and interior side of the glass permitted discriminating between colored pot metal glass and multi-layered flashed glass as well. Finally, the benefit of obtaining compositional information from the entire surface, as opposed to point analysis, was illustrated by the discovery of what appears to be a green cobalt glass—a feature that was previously missed on this well-studied stained-glass window, both by connoisseurs and spectroscopic sample analysis.