Odour that may be released when opening packaging of plastic objects is often a concern for collection managers. Volatile compounds emitted by three separate plastic-coated textile objects from Centraal Museum Utrecht were identified. Samples are analysed with Fourier Transform Infrared Spectroscopy (FTIR) and (pyrolysis) Gas Chromatography Mass Spectrometry (GC/MS). Polar and apolar Magic Chemisorbers are used to trap volatile organic compounds (VOCs) that the plastic coatings are off-gassing. Two of the objects have a plasticised polyvinylchloride (PVC-P) coating giving off a faint chemically sweet smell, where the DEHP plasticiser is detected as the main off-gassing compound. The third object has a polyurethane (PUR) ester coating which has a very rancid smell, most likely a result of the off-gassing of butanoic acid and naphthalene derivatives. This pilot study shows that polar (PEG) and apolar (PDMS) Magic Chemisorbers are useful sorbents to trap compounds that are off-gassing from plastic coatings.

This research provides new insights into the composition of zinc white paints used by Piet Mondrian during his neoplastic period. Nine paintings, dated between 1921 and 1935, were studied, with a focus on three works in the collection of the Fondation Beyeler (Basel, Switzerland)— Tableau I (1921–1925), Co mposition with yellow and blue (1932) and Composition with double line and blue (1935)—and on Lozenge composition with yellow lines (1933) in Kunstmuseum Den Haag (The Netherlands). Cross sections from other paintings, most of which previously studied by Van Asperen de Boer in the early 1990’s, were reexamined as well. The analyses revealed a zinc white paint with aluminum phosphate inclusions (ZW-Al/P). In two of the works, a zinc white paint with aluminum sulphate was also found. The occurrence of aluminum phosphate (or aluminum sulphate) in 1920–1930’s paint formulations, and in paintings by Mondrian, has never been reported so far. Likely, the use of this zinc white paint in Mondrian’s and other artworks is more widespread than currently known, but it may have been overlooked in similar case studies, since its identification can only be accomplished with detailed scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM–EDX) analysis of cross sections. Mondrian’s use of pure ‘bright’ ZW-Al/P paint is limited to the later paintings (1932–1935) of this study, whereas in the earlier works (1921–1929) it was mostly mixed with lead white, likely conveying a different hue. Both the ZW-Al/P and Zn-Al/S ‘marker paints’ were also added to yellow, blue or black paint in specific paint layers of the planes and lines, respectively. It was also shown that Mondrian used the same paint on the frames as in the white planes and that the frames were painted while still working on the composition, and not only when he considered the work completed. Indeed, the detection of the zinc white marker paints might help to delineate the chronology of Mondrian’s working process in other paintings and may also be important in the interpretation of overpaints in the course of a treatment when removal of certain paint layers is considered.

Vincent van Gogh’s painting Congregation Leaving the Reformed Church in Nuenen from the collection of the Van Gogh Museum in Amsterdam was executed in 1884 and partially repainted by the artist in 1885. The painting was restored in 1961, however, the details of this treatment were not documented. After being stolen from the museum in 2002 and finally recovered in 2016, the Church was subjected to an extensive technical examination campaign which started in 2017. The aims were to: characterise the stratigraphy of both initial and later paint layers (including identification of the painting materials used by Van Gogh), evaluate the condition of the painting and assess the feasibility of the desired restoration treatment. Portable X-ray fluorescence spectrometry (XRF) was performed to non-invasively identify elements related to pigments in the paint layers of the two painting campaigns. To further identify constituent materials and comprehend the painting’s complex stratigraphy, a single paint sample was collected and embedded in resin for analysis by means of Optical Microscopy, Scanning Electron Microscopy with Energy Dispersive X-ray spectrometry (SEM-EDS) and Fourier Transform Infrared spectrometry - Attenuated Total Reflectance (FTIR-ATR). Additional non-invasive measurements were performed in a MOLAB campaign in 2018 by two complementary and portable analytical techniques: Optical Coherence Tomography (OCT) and reflection FTIR spectroscopy were used to gain further insight into the painting’s stratigraphy and identify surface layers across various regions of the painting. The presence of an original varnish under the paint from 1885 (and therefore likely applied by Van Gogh himself) was revealed by OCT. It was characterised as being protein based by FTIR-ATR and reflection FTIR spectroscopy. Based on the knowledge on the artist’s varnishing practice, it could be concluded that this most likely concerns an egg white varnish for the first time found in an early work by Van Gogh. The upper varnish layer, however, was identified as an alkyd resin applied during the aforementioned 1961 treatment. The combined use of FTIR and OCT enabled non-invasive in situ assessment of solvent cleaning procedures aimed at the selective removal of the 1961 restoration varnish with the preservation of Van Gogh’s original varnish. Specifically, OCT and FTIR analyses were carried out before, during and after each cleaning test to carefully assess the condition of the painted surface and that of the original varnish. The results of the cleaning tests aided in fine-tuning the procedure of varnish removal during the restoration process.

This study focuses on copper green glazes on the front and reverse schemes of a seventeenth-century harpsichord lid painting. The aim was to investigate the materials and techniques of the copper-based green paints and their brown discolouration, a phenomenon commonly encountered in glazes made with the pigment verdigris (basic and neutral copper acetate). The study summarises the historical materials and recipes for copper green glazes, and includes a review of hypotheses that have been proposed for discolouration, focusing on findings from investigations that have been conducted in laboratory environments into the chemical interactions between verdigris and linseed oil. Analyses, using optical microscopy, SEM-EDX, XRD, THM-Py-GC-MS and ATR-FTIR, were conducted on paint samples from the browned copper green glazes from the front and reverse of the painted lid. To link the laboratory studies with the information known from historical texts and technical analysis of the object, analysis was also conducted in tandem on reconstructions, comprising neutral copper acetate in linseed oil. These were made and previously studied as part of the MOLART project (1995-2000), based on historical paint recipes. The analysis of the MOLART reconstructions supports the idea of a correlation between pigment-medium interaction and oxidation. Results from analysis of the painted lid support the idea that artists used a range of copper-based pigments for green glazes besides copper acetate, and illustrate different techniques for the glazes used within the interior and exterior painted schemes.

One of the most intriguing periods of activity of Dutch painter Piet Mondrian (1872-1944) regards the transition between the early figurative works and the well-known neoplastic paintings. Three paintings from the collection of the Fondation Beyeler in Basel Switzerland made in this period were studied. In Eucalyptus (1912) and Composition No. XVI ('Arbres') (1912/13) the tree motif is still visible; Composition No. VI ('Blue Facade') (1914) refers to the side wall of a house, showing the traces of an adjoining building that had been demolished. For this paper, both the results of the in-depth examination by the conservators and the analyses of the heritage scientists were brought together. The goal was to compare the materials and techniques of these three early paintings and find trends of Mondrian's working process. All paintings were examined in detail, with the aid of stereomicroscopy, Xrays and technical imaging. Analyses of the canvas, pigments and binders were performed with non-invasive X-ray fluorescence (XRF) and Raman spectroscopy, and micro-invasive analysis of cross sections and loose material using optical microscopy, Raman and Fourier x-ray fluorescence spectroscopy (SEM-EDX and Pyrolysis Gas chromatography mass spectrometry (PY-GC-MS). The three works have been executed on linen canvas with commercial grounds of different compositions. The pigments of all paint layers could be identified, as well as linseed oil, used as binding medium in all paints and grounds. Special attention was paid to the technique of the black lines and underdrawings.

The most common method chosen by artists, designers, and craftsmen to realize artworks and objects with transparent poly(methyl methacrylate) (PMMA) is to bond pieces from premanufactured sheets using solvents or adhesives. This method is considered relatively easy to use, however achieving bonds that are both transparent and strong can be difficult. Artifacts from museum collections made by bonding transparent PMMA often exhibit a variety of bonding defects and failures not yet addressed in depth in the conservation literature. Therefore, an international project started with the aims of classifying these bonding issues and understand their causes. This paper presents the results of the first part of this project which included the following research activities: surveys of bonding defects in PMMA artworks and design objects in museum collections, a literature review of the most recommended materials and methods used to bond PMMA over time, the preparation of bonded PMMA mock-ups based on literature review, chemical characterization of the bonding materials, thermal ageing of mock-ups, and finally technical examinations of the PMMA bonded mock-ups. The main defects observed in the museum objects surveyed were successfully recreated in the lab and the causes of their formation were assessed. (c) 2020 J. Paul Getty Trust. Publi & eacute; par Elsevier Masson SAS. Cet article est publi & eacute; en Open Access sous licence CC BY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/4.0/).

The Rijksmuseum holds four valuable albums with 187 photographs made by Eduard Isaac Asser (1809-1894), one of the first figures in photography in the Netherlands. Based on visual examination, most of these prints have been identified as salted paper prints with a coating, but they can be hard to distinguish from matte or glossy albumen prints, especially where the coating is thick. In order to be more accurate in our descriptions and to better understand Asser's technique, a technical study of his work was conducted. Fourier transform infrared spectroscopy (FTIR) helped us to identify, to a certain extent, the nature of the coatings. Before the analysis, the prints had been described either as "shellac coated" or as "waxed," based on their varying degree of sheen. FTIR identified a larger number of substances in the coatings: gum, protein, natural resin, and possibly starch. Optical coherence tomography (OCT) was also used to study the coatings. Because OCT has limitations when dealing with very thin layers, it was not always suitable for distinguishing coated salted paper prints from coated albumen prints. However, it did turn out to be a useful tool to explore the topography and structure of the paper supports and the coatings.

Johannes Vermeer (1632–1675) is known for his brilliant blue colours, and his frequent use of the costly natural ultramarine. This paper reveals new findings about ultramarine in the headscarf of Girl with a Pearl Earring (c. 1665, Mauritshuis). The painting was examined using a range of micro- and macroscale techniques as part of the Girl in the Spotlight research project (2018). Analysis of micro-samples mounted as cross-sections using SEM–EDX and FTIR-ATR showed that Vermeer used high-quality ultramarine in the blue headscarf, based on the relative abundance of bright blue particles of lazurite. Analysis with synchrotron sulphur K-edge XANES suggested that the ultramarine pigment was prepared—at least in part—from a heat-treated lapis lazuli rock. The entire painting was imaged using MS-IRR, MA-XRF, RIS, and digital microscopy to reveal the distribution of materials of the headscarf, and to give more insight into Vermeer’s painting process. The shadow part of the headscarf has a remarkably patchy appearance, due to paint degradation that is probably related to the large amounts of chalk Vermeer mixed in the ultramarine paint in this area. The question was raised as to whether extra chalk was added deliberately to the paint to adjust the handling properties or opacity, or whether the chalk was the substrate of a—now faded—yellow lake. Schematic paint reconstructions were made to investigate the effect of the addition of chalk or yellow lake on the paint properties. The analyses and reconstructions led to the hypothesis that the blue headscarf originally contained a wider range of different blue colour shades: an opaque light blue for the left (lit) zone, a slightly brighter opaque blue for the middle zone, and a deep dark blue-green glaze with alternating blue-green glazing brushstrokes for the shadow zone—now largely compromised by paint degradation.

The soft modelling of the skin tones in Vermeer’s Girl with a Pearl Earring (Mauritshuis) has been remarked upon by art historians, and is their main argument to date this painting to c. 1665. This paper describes the materials and techniques Vermeer used to accomplish the smooth flesh tones and facial features of the Girl , which were investigated as part of the 2018 Girl in the Spotlight research project. It combines macroscopic X-ray fluorescence imaging (MA-XRF), reflectance imaging spectroscopy (RIS), and 3D digital microscopy. Vermeer built up the face, beginning with distinct areas of light and dark. He then smoothly blended the final layers to create almost seamless transitions. The combination of advanced imaging techniques highlighted that Vermeer built the soft contour around her face by leaving a ‘gap’ between the background and the skin. It also revealed details that were otherwise not visible with the naked eye, such as the eyelashes. Macroscopic imaging was complemented by the study of paint cross-sections using: light microscopy, SEM–EDX, FIB-STEM, synchrotron radiation µ-XRPD and FTIR–ATR. Vermeer intentionally used different qualities or grades of lead white in the flesh paints, showing different hydrocerussite/cerussite ratios and particle sizes. Lead isotope analysis showed that the geographic source of lead, from which the different types of lead white were manufactured, was the same: the region of Peak District of Derbyshire, UK. Finally, cross-section analysis identified the formation of new lead species in the paints: lead soaps and palmierite (K 2 Pb(SO 4 ) 2 ), associated with the red lake.

This chapter considers the conservation of Van Gogh’s Sunflowers, now at the Van Gogh Museum in Amsterdam, from past to future. It starts with the two main episodes of treatment performed in 1927 and 1961 by the Dutch restorer, Jan Cornelis Traas. Archival research provides an outline of Traas’s training, career, methods and approach viewed in the context of his day. Technical and scientific investigation of the Sunflowers helps understand what these former treatments by Traas (which are barely documented) entailed. Based on these insights, the condition of the painting is appraised and a conservation strategy defined. The past interventions severely limit options for renewed treatment. On balance the tendency is firmly towards preventive conservation, with only minor restoration performed.

This study evaluates two research projects and treatments performed ten and twenty years ago by the Cultural Heritage Agency of the Netherlands (RCE) on two artworks made of flexible polyurethane ether foam (PUR foam) by Piero Gilardi; Natura Morta (1967) of the collection of Museum Boijmans Van Beuningen, Rotterdam (NL) and Zuccaia (1991) of the collection of Zoetermeer City hall (NL). These projects and treatments on the objects involved the treatment of mechanical damages present in the works, and the development and performing of the consolidation of PUR ether foam with Tinuvin B75/Impranil DLV mixture. The condition of an untreated nature carpet Cavoli e Neve (1967, 1988) from the collection S.M.A.K., Gent (BE) was used as a control reference in this study. The techniques from the two former RCE researches, such as determination of cell strut size and hydroxyl index, are used for the evaluation of the effectiveness of the past treatments. Besides that, empirical research, i.e. resilience and rubbing tests, are performed on all case studies. Also, the consolidation method used in the treatment of the abovementioned artworks was evaluated and refined. Finally, consolidation tests on artificially aged and severely degraded PUR-foam samples were carried out to see whether the condition of already degraded foam could also be reinforced. This study showed that the effectiveness of the former treatments was best assessed by the measurement of the cell strut size and empirical research. The past treatments proved to be very successful and can therefore be suggested for similar artworks. After the promising results of this study, Cavoli e Neve was treated. However, preliminary consolation tests on the artwork itself showed, viewing the foam under microscope, the skeleton still broke during consolidation and therefore did not improve the skeleton strength. Therefore, besides cleaning the work and structural treatment of the damages, a consolidation on this artwork was not performed. Ongoing research will focus on this issue.

The observation of disfiguring yellow oil-like material on the surface of paintings by the contemporary Dutch artist Erik Oldenhof led to an investigation of the material and environmental factors causing the migration and surface deposition of the exudate. A combination of material analysis, the examination of artificially aged reconstructions and information provided by the artist and paint manufacturer, Royal Talens, provided evidence that the phenomenon is related to the drying properties of the safflower oil used, the artist's use of thick paint layers and the availability of light while the paint is drying. Reconstructions demonstrated that the exudation phenomenon can be reproduced and is not restricted to one particular range of oil paint or manufacturer.Visual characteristics of the exudate, including its appearance in UV light and SEM back-scattered images, were documented, and the organic and inorganic components of the paint were characterised by SEM-EDX, XRF, THM-PyGC-MS and FIR. Results confirmed that the exudate is composed of safflower oil derived from the paint binding medium, and that a difference in P/S ratio between the exudate and paint bulk is due to the presence of metal stearates in the paint that have not migrated to the surface. (C) 2015 Elsevier B.V. All rights reserved.

Two large Viennese folding screens were found during reconstruction work in the attic of the Liechtenstein City Palace in Vienna, Austria. The screens date to the middle of the nineteenth century a...