Correction to: Conservation of Modern Oil Paintings

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IPERION HS D.5.3 Protocol to monitor objects and environment for preventive conservation and concept of digital platform infrastructure for preventive conservation

<p>The scientific understanding of the degradation of cultural heritage objects, caused by external and internal factors, is increasing. However, we are still far from having a comprehensive material–object–environment–building model that would enable us to predict the outcomes of preventive conservation scenarios. This deliverable represents a step forward in detecting, understanding, and monitoring changes, crucial for preventive conservation. It targets oil paintings and addresses various internal and external factors. The deliverable is organized into three topics, each containing subprojects, and covers protocols development for chemical and structural painting changes (Topic 1), monitoring indoor environmental conditions (Topic 2), and a digital platform with decision support tools (Topic 3). Twenty-five partners from 13 countries contributed to the deliverable, and each subproject is coordinated by a project leader.</p><p>Topic 1, the first project focuses on the development of a protocol for assessing light-induced color changes in specific pigments within oil binder, utilizing non-invasive imaging and single-point techniques as well as micro-destructive molecular and elemental methods. Objectives include evaluating different white-light sources' impact on mock-ups and defining critical parameters for monitoring paint film color changes. The second project introduces the monitoring of lead soap protrusion formation. It combines non-invasive imaging and spot-point techniques, resulting in a ten-step protocol for long-term condition monitoring. For varnish analysis (project 3), a toolkit of non-invasive chemical and structural techniques is applied, showing promising advances in sensitive equipment, but necessary development for effective museum implementation. The fourth project aids in interpreting multimodal methodology results for sensitive modern oil paint surfaces. While some techniques provide initial insights, conclusive findings require cross-referencing with additional non-invasive methods. The topic's final project explores non-invasive imaging for determining and monitoring delaminating and flaking paint layers. Most of the techniques discussed in Topic 1 are offered via the IPERION HS catalogue of services.</p><p>Topic 2, the first project in this topic, aims at developing a toolkit for simple environmental monitoring techniques. It specifically examines formic and acetic acid, known risks to collections during storage or display, and validated them with samplers for SO2 and NO2. The developed method is offered as an IPERION HS service. The second project carried out an interlaboratory comparison of the Oddy Test to assess its reproducibility and progress toward standardization. In addition, it compared protocol variations and shares more objective assessment approaches and best practices. The third project offers a concise protocol and overview of instrumental techniques available through IPERION HS for analyzing the chemical composition of collected airborne particles. This analysis aids in identifying pollutants, understanding their sources, evaluating their impact on artworks, and devising protection strategies for cultural artefacts. The last project demonstrates the value of incorporating different mass spectrometry approaches for the detection of organic compounds harmful to oil paintings and optimized their protocols.</p><p>Topic 3 focuses on enhancing and openly sharing a digital platform of specialized apps for preventive conservation, including HERIe, DISCOLL, IMPACT, and Collection Demography apps. In addition, it describes the requirements of ideal apps for the end-user and includes a validation of the dust deposition model for the case study of the cloister of the Monastery of Santa María del Paular (Rascafría, Spain). The digital apps are presented on a single website, the E-RIHS - Digital Tools, Services and Resources, <a href="https://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fe-rihs.io%2Fresources.html&data=05%7C01%7CL.van.Rooij%40rijksmuseum.nl%7C5fb18fc7e5cf4ca9b36408dbb223f4ed%7C635b05eb66c748e1a94fb4b05a1b058b%7C0%7C0%7C638299639760714426%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=%2BiDTMCrN%2BAsncVDIPGgPtmbe2wqp8s%2FghrWFPZwxyEY%3D&reserved=0">https://e-rihs.io/resources.html</a>,  planned to be merged in E-RIHS - ERIC DIGILAB open services. </p><p>To conclude, topic 1 protocols are based on mock-ups, and serve as the foundation, and starting point for actual implementation in authentic paintings. The various protocols developed under topics 1 and 2 serve as a 'monitoring toolkit' which can be offered to E-RIHS users in the future and the concept of the digital platform presented here will be fused in E-RIHS - ERIC DIGILAB open services. </p&gt

Soft X-ray nanospectroscopy for quantification of X-ray linear dichroism on powders

International audienceX-ray linear dichroism (XLD) is a fundamental property of many ordered materials that can for instance provide information on the origin of magnetic properties and the existence of differently ordered domains. Conventionally, measurements of XLD are performed on single crystals, crystalline thin films, or highly ordered nanostructure arrays. Here, it is demonstrated how quantitative measurements of XLD can be performed on powders, relying on the random orientation of many particles instead of the controlled orientation of a single ordered structure. The technique is based on a scanning X-ray transmission microscope operated in the soft X-ray regime. The use of a Fresnel zone plate allows X-ray absorption features to be probed at ∼40 nm lateral resolution - a scale small enough to probe the individual crystallites in most powders. Quantitative XLD parameters were then retrieved by determining the intensity distributions of certain diagnostic dichroic absorption features, estimating the angle between their transition dipole moments, and fitting the distributions with four-parameter dichroic models. Analysis of several differently produced ZnO powders shows that the experimentally obtained distributions indeed follow the theoretical model for XLD. Making use of Monte Carlo simulations to estimate uncertainties in the calculated dichroic model parameters, it was established that longer X-ray exposure times lead to a decrease in the amplitude of the XLD effect of ZnO

After the paint has dried: a review of testing techniques for studying the mechanical properties of artists’ paint

Abstract While the chemistry of artists’ paints has previously been studied and reviewed, these studies only capture a portion of the properties affecting the response of paint materials. The mechanical properties of artists’ paints relate to the deformation response of these materials when a stress is applied. This response is dependent on many factors, such as paint composition, pigment to binder ratio, temperature, relative humidity, and solvent exposure. Here, thirty years of tensile testing data have been compiled into a single dataset, along with the testing conditions, to provide future researchers with easy access to these data as well some general discussion of their trends. Alongside the more commonly used techniques of tensile testing and dynamic mechanical analysis, new techniques have been developed to more fully investigate the mechanical properties, and are discussed along with salient results. The techniques have been divided into two categories: those that are restricted to use on model systems and those that are applicable to historic samples. Techniques applied to model systems (tensile testing, dynamic mechanic analysis, quartz crystal microbalance, vibration studies) require too large of a sample to be taken from art objects or focus on the mechanical properties of the liquid state (shear rheometry). Techniques applied to historic samples incorporate the use of small sample sizes (nanoindentation), optical techniques (laser shearography), computational simulations (finite element analysis), and non-invasive comparative mechanical properties (single-sided nuclear magnetic resonance) to investigate and predict the mechanical properties of paints

X-ray Nanospectroscopy Reveals Binary Defect Populations in Sub-micrometric ZnO Crystallites

International audienceBesides its many applications in electronics, photonics, and catalysis, ZnO has also been extensively used as the pigment zinc white ever since its introduction in the first half of the 19 th century. It is shown here that zinc whites (ZnO formed through zinc vapor oxidation) form a chemically binary system, with each of the submicrometric crystallites belonging to either of two distinct classes. The observation of the two classes is done based on X-ray absorption nanospectroscopy and was determined to be caused by differences in the populations of anisotropic crystal defects. A theoretical assessment of the vapor oxidation synthesis method is formulated which predicts that the binary distinction in crystal defect populations is caused by local variations in synthesis parameters. As the crystal defect population in ZnO has been shown to be related to its catalytic properties, these results provide fundamental insights on the link between the intrinsic properties of zinc white and its degradation issues in oil paint