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Most garments in museum collections have belonged to people of high societal status. Clothing of the common people, however, has rarely been preserved. Because of this, the conservation of such rare items is of special importance. The current study focuses on such an object from the Rijksmuseum collection; a pair of eighteenth century breeches that were retrieved from an anonymous grave on Spitsbergen. As these breeches contain several unidentified materials, it is unclear how best to conduct the conservation of the object. The identification of trace material plays a key role within criminal law and therefore, it is hypothesized that a forensic approach could provide a suitable framework within this case of cultural heritage as well. After forensic examination, trace material was analyzed using a microscopy-based approach and was found to be mainly of biological origin. Energy-dispersive X-ray (EDX) and Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy indicated the presence of human skin remains. It was concluded that a modern forensic approach can successfully be applied to a historical object within cultural heritage and can assist decision-making regarding possible future conservation of the object. The systematic application of the forensic methodology was found to be appropriate with little to no modification to classify and identify trace materials, but further improvements could be made. The current work should be seen as a starting point that allows for more questions regarding museum objects to be answered in a forensic manner, including aspects such as authenticity, the chain of custody, the context, original use and object conservation.

Oil paint is a dynamic system that undergoes chemical alteration on several time and length scales. At the short term, curing reactions are necessary for oil to dry properly. At longer time scales, a wide variety of other chemical processes can negatively affect the visual appearance or mechanical properties of historical artistic paint systems. The development of chemical imaging methods capable of covering length scales continuously from the millimetric to micro- or even nanoscale is key in understanding the chemical composition of a painting and the historical changes thereof. Such imaging methods can help in assessing to which extent the original painting’s composition may have been modified by chemical degradation processes. Processes that occur in the highly heterogeneous mixtures of binders, pigments, additives, alteration products and possibly later repainting and restoration treatments. Establishing the precise biography of the painting contributes to evaluate its authenticity. New modalities and novel methods of microchemical imaging provide access to previously unexplored length scales, are capable of better differentiation between the various oil paint components (original composition or later addition), and allow performing faster analysis to produce higher definition images. In this review, we report on recent methodological developments and future prospects to determine oil paints composition using microchemical imaging at the micro- and nanoscale.

This chapter covers instrumental methods of analysis used by conservation scientists and their research associates in universities and national conservation and research facilities. Many journals and conferences covering the conservation and analysis of the moveable heritage – which includes paintings – and professional bodies which acted as publishers and organisers, were instituted from the early 1950s onwards. The electrons in the beam have different interactions with the paint sample: different detectors can provide information about the surface topography, paint morphology and stratigraphy, or else the elemental composition of paint samples. There are great advantages to having one conservation scientist or conservator carry out all the X-ray analysis for the institution, to maximise the benefit of experience with different sample types. There is a wide range of organic constituents in paints ranging from single molecules like wax esters in beeswax or terpenoids in varnishes to large natural and synthetic polymers.

The science department at the Rijksmuseum encompasses a large group of scientists with different specialisms. We conduct research on our collection in close collaboration with conservators, curators and (technical) art historians, with the aim of better understanding, managing and presenting the collection. At HIMS, we study fundamental chemical processes in paints. Dividing my time between the two roles means that I can function as a bridge (or translator) between the art and academic fields.

This paper discusses decision-making processes for the treatment of oil paintings (1950s–present) exhibiting oil exudates (This research was performed by Jazzy de Groot in 2016 as a part of the post-graduate paintings conservator training at the University of Amsterdam.). Oil exudates and ‘drips’ that exude from the paint, can have different appearances, liquid to solid and transparent to opaque. How practicing conservators treat paintings exhibiting such phenomena was established by interviews and questionnaires as well as a review of published treatments. Factors that influence decision-making processes turned out to be, among others, the possible cause, the artist intention, the extent to which exudates disturb the painting and priorities during treatment. Conservators are generally reluctant to remove exudates, especially when exudates are older. The main factors contributing to this reluctance are the uncertainty about their origin and the fact that exudates are not always considered disturbing for the image. Further research into how to detect, determine and evaluate the possible consequences of exudates will help conservators to make better-informed decisions for the treatment of paintings on which they occur.

This research investigates the effects of varnish removal from oil paintings using Evolon® CR microfibre cloth. Nine interviews were conducted with conservators, leading to an inventory of current Evolon® applications. Based on the interviews, experiments were devised to assess the properties of Evolon® and its effects during varnish removal from oil paintings in comparison to cotton swabs. Observations were made using the naked eye, microscopy (stereomicroscopy, Hirox®3D Digital Microscopy, Micro Reflectance Transformation Imaging (Micro-RTI)) and photography in both ultraviolet (UV) and daylight fluorescent lights. Furthermore, the solvent distribution behavior for the different application methods was visualized using a gelatin substrate and a fluorescein isothiocyanate (FITC) fluorescent stain in ethanol. Application methods influence the efficacy of varnish removal, the solvent effect on the (paint) surface, the amount of solvent used and the solvent distribution. In general, this research revealed that in comparison with the use of cotton swabs, Evolon® facilitates the use of lower amounts of solvent and a reduction in mechanical action at the paint surface. This is potentially advantageous for cleaning solvent-sensitive paint surfaces. This practical approach will serve to guide conservators considering using this material for the first time.

This study investigates the use of an ultrasonic mister and hydrophobization with a silicone solvent barrier for the surface cleaning of water sensitive oil paints. Details are presented regarding the reconstruction of water sensitive paints through the growth of epsomite crystals on contemporary Winsor and Newton (W&N) oil paints via exposure to sulphuric gases, using samples that had been previously artificially aged and soiled. These samples were subsequently used for surface cleaning evaluations, specifically tailored to water sensitive oil paints. A number of aqueous solutions were tested with different application methods, including swabs and application with an ultrasonic mister in combinations with a brush and Evolon® tissue. Additionally, gels prepared with aqueous based solutions were tested with and without prior hydrophobization of the surface with silicone solvent cyclomethicone D5. The application of aqueous solutions with the mister were found to decisively reduce pigment removal from the water sensitive paints when compared to swab application. It was also found that the use of a cyclomethicone D5 solvent barrier reduces pigment removal during spreadable gel cleaning.

We are at present closer to the ‘original state’ of any artwork than anyone in the future will be. This proximity creates a particular urgency to document artworks before significant changes occur through ageing, handling or treatment; and whilst the works can still be interpreted within their contemporary context. Recording the appearance, materials, meaning and artistic intent will enable others to make more informed decisions about the treatment and display of the artworks as they progress through time (and away from their original context and initial material state). This paper explores this concept through the results of case study research of a painting by the American artist Robert Ryman from the collection of the Stedelijk Museum Amsterdam. Because various other artists worked in a similar abstract style during the same period, Ryman’s works are prone to ill-matched comparison and confusion regarding his artistic intent. During this research interviews with the artist and prominent conservators and scholars of his oeuvre were scrutinized for statements about his artistic intent. This provided a greater understanding of Ryman’s body of work as the basis for formulating some guidelines for consideration when treating similar works by the artist.

The privately owned oil painting Composition with Color Planes 4 (1917) by Piet Mondrian (1872–1944) has been the subject of ongoing investigation since 2011. The painting consists of color planes in a field of differing whites. Some~of these white areas suffer from delamination issues, in combination with flaking. Previous research demonstrated a link between the presence of zinc oxide and the delamination phenomena. More recently, the formation of zinc soaps was found to play a role. In this study, cross sections from both delaminating and relatively intact white areas were investigated with light microscopy, SEM-EDX, and ATR-FTIR imaging to obtain more information about the stratigraphy and condition of the paint layers. Two stages in metal soap formation were identified in the delaminating areas. The first stage consists of noncrystalline zinc soaps or zinc ions bound to carboxylate functional groups in the polymerized oil network. Crystalline zinc soaps, which represent the second, final stage of metal soap formation, are generally linked to the development of zinc soap related deterioration phenomena. In this case, they were found at the interface between the delaminating paint layers. Possible implications for treatment and factors that might trigger further delamination will be discussed.

The early twentieth century oil painting Beach Scene had severe delamination problems. The painting consisted of an oak panel primed with three white, oil-based ground layers with several oil paint layers on top. The reverse of the panel was varnished. The delamination occurred at the interface between the first ground layer and the panel. A brownish, semi-translucent zone was visible at the bottom of the first preparation layer. Material analyses with SEM-EDX, FTIR-ATR and THM-Py-GC/MS offered insight into the materials present and their degree of deterioration. The brownish zone was explained as dissolution of the zinc white pigment by (fatty) acids from the panel and the oil binder. It was hypothesised that the glazed framing system of the painting restricted natural expansion and contraction of the tangentially cut panel in fluctuating climate. Compression shrinkage then caused tenting of the paint film. This study improved our understanding of Akkeringa’s painting technique and the current condition of the painting. The study also provided support for future decisions on treatment and preventive conservation measures not only for Beach Scene, but also for Akkeringa’s other works on panel.

Edvard Munch’s (1863–1944) unvarnished oil paintings (1909–16) in the Aula of the University of Oslo have a long conservation history, including issues associated with soiling and cleaning. Despite the high frequency of previous cleaning campaigns, the removal of dirt and soot from these surfaces continues to be a challenge. This paper relates to ongoing research into novel methods for surface dirt removal (soft-particle blasting CO2-snow, and Nanorestore Gel® Peggy and Dry series). The paper discusses the first steps of this research, focussing on the preparation of mock-up painting samples that will be used to evaluate the effects and to optimise these methods, hence the rationale and limitations of using simplified samples to represent real paintings are discussed. The aim of the wider study is to devise appropriate cleaning strategies for the Aula paintings.

This paper presents a survey of the issues conservators encounter when surface-cleaning paintings by Asger Jorn, with the aim of contributing to the formulation of best practices for cleaning Jorn’s and similar paintings.Nine interviews were conducted with experienced conservators working throughout Europe. In addition, the conservation reports of 95 of Jorn’s paintings were studied and 34 works were visually assessed.Conservators are conservative in their approach when surface-cleaning Jorn’s paintings, which are described as suffering from cracked, brittle and powdery paint, soft paint with imbibed dirt and water and solvent sensitivity/solubility. They feel that Jorn’s unstable materials and paint modifications strongly limit the range of safe cleaning treatments. Conservators fear removing original material and unwanted optical or chemical changes. Time-consuming preliminary examinations and extensive testing followed by careful treatments that utilise different cleaning methods per colour, appears to be the approach favoured most commonly by the conservators interviewed.

In modern studies of Dutch art, the makers of decorative paintings in the 17th and 18th centuries are usually referred to as ‘decorative painters’ or ‘interior painters’, as if this was a profession in its own right. However, neither name existed at the time. In the 17th and 18th centuries, the painter’s trade - defined in the regulations of the Guild of St Luke - encompassed two separate and independent groups: the artist painters and the coarse painters. Because the best-known ‘decorative painters’ were also recognised artist painters, in art history the painting of decorations has come to be regarded as primarily their work. Archival research, however, has revealed that it was not unusual for a painted decoration to be the result of close collaboration between artist painters and coarse painters. In some cases a highly complex decoration actually proves to have been made by a coarse painter working alone. This will be demonstrated by reference to a painted chamber in Almelo dated 1778. Technical research has shown that all the painted work was executed by a coarse painter.

The restoration of the ‘painted chamber’ in Beverwijk by Jacobus Luberti Augustini instigated an in-depth technical study of the room and its painted canvas wall hangings. Through close observation with the naked eye, ultraviolet light, infrared reflectography and the study of paint samples in combination with art historical and archival research and information from contemporary art technological sources, insights were provided into the production practice of an 18th-century painted wallhanging factory (a so-called behangselfabriek, a large workshop in which several painters worked together on painted wall hangings under the supervision of one painter). Research showed that within the same room different types of canvas and grounds were used. The canvases were prepared in the workshop in such a way that seams would not be visible, following the instructions of Lambertus Simis as cited in his painting treatise of 1801. Infrared reflectography and the study of the painting technique revealed various types of underdrawing and painting methods, demonstrating the different hands that worked on the ensemble. To guarantee the overall unity and ensure the optical illusion of the painted ensemble, several measures were taken such as indications of the same level of the horizon throughout the individual landscape paintings, working instructions inscribed on the reverse of the canvases, and painting the canvas borders surrounding the landscape paintings and wooden panelling in the room all at once in situ.

The painting Couple with Clouds in their Heads by Salvador Dalí (1936) from the Museum Boijmans van Beuningen in Rotterdam was seriously disfigured by ring formations on the edges of the painting and a matt, white-looking semi-transparent material on the surface. Paint samples, taken from affected and unaffected paint areas, investigated with light, scanning electron and ATR-FTIR microscopy and X-ray diffraction showed that the zinc white-containing oil paint was converted into zinc soaps, zinc formate dihydrate, zinc acetate dihydrate and zinc sulfide. The conversion of the zinc white started at the surface of the painting. Zinc soaps are formed by a reaction of zinc white and fatty acids from the oil. Formate and acetate, most likely emitted from the wooden frame, reacted with the zinc white pigment. Finally, the zinc sulfide is suggested to derive from zinc white reacting with hydrogen sulfide.The high degree of degradation of the zinc white-containing paint and the ring formation is postulated to be triggered by the exposures of the panels to high temperatures which occurred during a 1-day photo shoot in 1936 shortly after completion of the paintings by Dali. Furthermore, it seems likely that the glazed frame created a (semi-)closed system and subsequently acid gasses diffused into the system via "leakages" due to a poor match between the frame and the panel, and may have initiated a reaction with the surface of the painting. As the glazed and framed panels were a non-ventilated system, the acid gasses did not distribute evenly over the surface, but rather were most intense at the edges of the painting. The ring formation caused by the gasses is compared with the phenomena of Liesegang rings, a reaction-diffusion process.

Metal soap efflorescent hazes and crusts are one of the most visually disturbing of all metal soap related alterations in paintings. The phenomenon presents particular challenges for conservators as the surface deposits that form are insoluble and intimately bound with the paint film. The superficial deposits accumulate following migration of metal carboxylates, a product formed within the paint film from reaction of free fatty acids with metal ions from pigments and/or driers. Upon deposition at the surface, the metal carboxylates undergo a process of remineralisation, the products of which are determined by the atmospheric conditions that the painting is exposed to. The material can appear optically similar to the whitish haze of organic efflorescence though manifestations also range from crystalline clusters to thick crusts, and in some cases the painting may consequently be rendered partially unreadable. This study aimed to investigate the removal of visually disturbing lead soap efflorescence with Ethylenediaminetetraacetic acid (EDTA), which sequesters the lead ions from the remineralised crust. Through a careful balance of variables such as pH, concentration and application, it is feasible to thin the superficial material significantly. By this means it is possible to saturate the surface of the paint film and render the previously disfiguring efflorescence transparent. Paintings previously treated with this method show no signs of recurrence and thus it appears to be a viable, long-term treatment option.

Contains fulltext : 101694.pdf (Publisher’s version ) (Open Access) Radboud Universiteit Nijmegen, 15 oktober 2012 Promotores : Hout, R.W.N.M. van, Baayen, R.H. xii, 151 p.

Contains fulltext : 43213.pdf (Publisher’s version ) (Closed access) April 2006 JADT Besancon

Contains fulltext : 41119.pdf (author's version ) (Open Access) The International Conference on Language Variation in Europe 2005 Amsterdam

Item does not contain fulltext Dag van de Fonetiek Utrecht

Contains fulltext : 42022.pdf (author's version ) (Open Access) Vancouver The Association for Computers and the Humanities/the Association for Literary and Linguistic Computing Conference 2005

Lead white is a lead (Pb) carbonate that has been extensively used throughout human history. Analysing lead isotope ratios of lead white potentially gives information on the provenance of the lead constituting the pigment. The extensive use of lead white in oil paintings until the 20th century, combined with lead isotope analysis, provides information not only on the provenance of the lead in the pigment but also on painting making processes, trading of lead, lead white throughout history and attribution and authentication. This research presents a comprehensive study of the application of lead isotope analysis to: - Improving analytical precision and sensitivity of lead isotope analysis - Investigating the heterogeneity of lead isotope ratios in lead white used within a single painting - Study of the time-dependant variation of lead isotope ratios of lead white in 17th century Dutch paintings - Use of lead isotope analysis of lead white in combination with other analytical techniques to study paintings The proposed development of improved and more sensitive analytical methods lead to the creation of a new sampling tool, named “micro-scalpel” that allows sampling from cross-sections. This instrument reduces the amount of pictorial material taken during the sampling, and allows the operator to selectively sample from one pictorial layer at a time. Simultaneously the analytical method was improved, increasing the sensitivity of the instrument (multi collector inductively coupled plasma mass spectrometer or MC ICPMS) with the application of a lead double spike (DS) technique and the use of a 1013 Ω resistor amplifiers. Due to the improved analytical sensitivity, the sample size required for analysis was reduced by a factor of ten with the use of 1013 Ω resistor amplifiers, while maintaining accuracy and precision. The new method was used to investigate the heterogeneity of lead isotope ratios within a single painting. The study was conducted on five Netherlandish paintings from the 17th century. Each painting was sampled several times (n. 5-20) in different areas. The data were then compared to the analysis of powdered lead white (historical Venetian lead white from the end of the 16th century rescued from a shipwreck). The study determined that the lead isotope ratios of the Venetian lead white pigment were homogeneous. In contrast, four out of the five paintings contain lead white samples that were outside analytical, identifying lead isotope ratios heterogeneity within the painting. The results suggest that the pigment, processed and used in the artist’s studio prior to painting could have been in contact with other lead-bearing compounds that altered the original isotopic composition. These findings suggest multi-sampling strategy, and the need of a database to compare data to have a reliable interpretation of lead isotope ratios. The lead isotope analysis of 77 dated Dutch paintings from 27 artists allowed assessment of the time-dependent variation of lead isotope ratios of lead white and the creation of a database. The lead isotope compositions recorded a clear time dependence identifying a shift in lead isotope ratios during the period 1642-1647, and a second change is indicated after 1680. The changes in lead isotope ratios in lead white were connected to historical events. For example, the period 1642-47 coincides with the English Civil War in the country that was the main producer of lead at the time. The identification of a time-dependent variation of lead isotope ratios of lead white gives the possibility to distinguish early and late works by individual artists active in the 17th century.