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This paper critically compares the performance of four non‐invasive techniques that match the accuracy, flexibility, time‐efficiency, and transportability required for in situ characterization of leaded glass windows: macroscopic X‐ray fluorescence imaging (MA‐XRF), UV–Vis–NIR, Raman spectroscopy, and infrared thermography (IRT). In order to compare the techniques on equal grounds, all techniques were tested independently of each other by separate research groups on the same historical leaded window tentatively dated to the 17th century, without prior knowledge. The aim was to assess the ability of these techniques to document the conservation history of the window by classifying and grouping the colorless glass panes, based on differences in composition. IRT, MA‐XRF and UV–Vis–NIR spectroscopy positively distinguished at least two glass groups, with MA‐XRF providing the most detailed chemical information. In particular, based on the ratio between the network modifier (K) and network stabilizer (Ca) and on the level of colorants and decolorizers (Fe, Mn, As), the number of plausible glass families could be strongly reduced. In addition, UV–Vis–NIR detected cobalt at ppm level and gave more specific information on the chromophore Fe2+/Fe3+ ratio. Raman spectroscopy was hampered by fluorescence caused by the metal ions of the decolorizer in most of the panes, but nevertheless identified one group as HLLA. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

A state-of-the-art method for non-invasive visualization of subsurface layers present in works of art is for the first time employed to study an Antwerp majolica tile tableau manufactured in the mid of the 16th century. Scanning macro x-ray fluorescence mapping (MA-XRF), was used to determine the characteristic elements of the renaissance majolica production and the pigments that were used for the colourful painting present on the tableau. Furthermore, the interpretation of the ensuing elemental images, allowed to visualize earlier retouchings and to distinguish original tiles from pieces that were introduced during 19th and 20th century restoration campaigns. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Magritte's composition La condition humaine, 1935 was found to conceal under its paint layers an entire quarter of a lost composition by the artist, until recently only known from a small black/white catalogue illustration- La pose enchantée, 1927. This study is the latest contribution to the discovery of the artist's missing painting, now known to have been cut into four parts and re-used by Magritte as the support for new compositions. Non-destructive analytical and examination methods and specifically macroscopic X-ray fluorescence (MAXRF) scanning and conventional X-ray radiography (XRR) were the two non-destructive analytical and examination methods used to study both compositions and add to the existing knowledge on the artist's palette during both periods. The first method is capable of identifying the presence and the distribution of key chemical elements present in artists' materials. In some instances elemental mapping provided useful information on the hidden painting, but conventional X-ray radiography (XRR) enabled a better visualisation of the form and paint application of the underlying composition. Furthermore, the turnover edges of the canvas reveal after over 80 years the artist's palette directly to the viewer. Additional XRF scanning of this exposed paint has confirmed and added to the existing research published to date of this lost painting, including a proposed colour reconstruction, but at the same time highlighting the need for further analytical research involving both non-destructive point analysis and the use of paint samples. [ABSTRACT FROM AUTHOR]