Lead White Pigment Research Articles

Technological research of Adalbert Erdelyi’s still life of the post-Budapest period

The study’s relevance lies in obtaining valuable information about Adalbert Erdelyi’s painting, which enhances the understanding of his artwork, supports efforts at accurate attribution, and enriches the study of art history. The purpose of this study was to characterise artist’s painting materials and technique of the post-Budapest period and introduce obtained results into scientific circulation. The research methodology was based on an integrated general scientific approach that combines theoretical and empirical methods, including art-critic and comparative analyses as well as optical and physicochemical methods. X-ray fluorescence analysis and Fourier-transform infrared spectroscopy were used to determine the artist’s pigment palette. Until now, only a few works of Adalbert Erdelyi’s early creative stage have been known and introduced into scientific circulation. A comprehensive study of Adalbert Erdelyi’s still life was carried out. The stylistic and technological features of the painting that were inherent in the post-Budapest period were established. It has been shown that cardboard made from a mixture of rag fibers and wood pulp was used as the painting support. The type of cardboard gluing and fillers were determined. The still life was painted wet-on-wet on the unprimed support without applying underdrawings. The analysis of the organic binder has shown that the painting was executed in the oil painting technique. Pure lead white was identified in white paints. Lead white with an admixture of zinc white, a mixture of lead white and zinc white, chrome yellow (lead chromate), vermillion, alizarin crimson, ocher, Emerald green (copper acetoarsenite), and Prussian blue were found in the paint layer. The identified pigments and a comparative analysis of oil polymerisation in lead white paint allowed us to confirm that the painting was created in 1918. It is shown that the artistic and style characteristics of the painting correspond to Adalbert Erdelyi’s post-Budapest period. Thus, “Still Life with Glasses on a Tray” can be considered the first known image of glasses with water in the artist’s creative heritage. The results of carried out research are an important informative source in the analysis of the artist’s early works and can be useful for art historians a nd curators of museum collections

Fracture toughness of aged oil paints

The fracture toughness in opening mode GIc for selected oil paints from Mecklenburg's Paint Reference Collection after approximately 30 years of natural ageing was determined using the procedure adopted from the ASTM D5528–13 standard in which double cantilever beam specimens are split in tensile tests. The careful reglueing procedure allowed multiple fracturing tests to be carried out that not only improved statistics of the measurements but also provided insight into the variation of the fracture toughness across the paint film observed for some paints. The latter was due to pigment sedimentation or chemical change of the oil binder as a result of the easier access of oxygen from the side open to the air. For the lead white paint, used over centuries both in paint films and oil grounds, the GIc values more than doubled from 18 to 39 J/m2 for three consecutive cracks formed at an increasing distance from one side of the paint film. The study demonstrated that fracture toughness corresponding to the first crack formation in aged oil paints ranged between 10 and 40 J/m2, relatively low values compared to the animal glue-based ground in paintings. In consequence, oil paints are more vulnerable to crack initiation and growth induced by tensile stress than the ground layer. The measurements filled the gap in the knowledge required for the analysis of fracturing or delamination processes in paintings.

Darkening of lead white in old master drawings and historic prints: A multi-analytical investigation

Old master drawings and historic prints often feature white highlights, which are typically painted using lead white, one of the most widely used historical white pigments. However, it has been observed that many of these highlights discolour over time, becoming dark brown or black due to unclear degradation processes. This phenomenon not only misrepresents the original artefacts, threatening their suitability for public display, but also diminishes their longevity. To ensure their preservation, it is essential to determine why some lead white highlights in these museum objects retain their light tones while others are prone to darkening. The objective of this study was to identify the relationships between the composition, provenance, and production methods of lead white pigments, and their role in the discolouration observed on drawings, lithographs and early photographs. Selected samples and artefacts were examined using a range of analytical techniques, namely X-ray fluorescence spectroscopy (XRF), X-ray powder diffraction (XRPD), and lead isotope analysis. While XRF analyses confirmed the presence of lead as the primary element in the majority of the highlights, XRPD measurements identified a variety of lead compounds such as the carbonates cerussite and hydrocerussite alongside galena—a black crystalline sulfide—and lead sulfates. Additionally, isotope analyses classified the lead raw materials into five main groups. Through these measurements, the examined lead white pigments were categorised based on their compositional properties in relation to the raw materials used, as well as their geographical and temporal origin. A significant finding is that lead white pigments from different production periods, spanning from older to more modern, may be characterised by varying proneness to discolouration irrespective of their provenance.

The Regulation of Lead White Paint in Conservation and Artistic Practice

ABSTRACT Lead white (basic lead carbonate), before its effective ban in much of Europe from 1989 onwards, was among the most versatile and widespread but also one of the most harmful pigments available. This paper is a critical discussion of the regulation of lead white paint and its consequences from the point of view of conservation and artistic practice in Europe. It looks at who benefited from exemptions to bans, and whether there was resistance to them. Buildings and artworks are both taken into account. The paper discusses nuances in regulation in four European countries which have notable differences in approach (France, Austria, Germany, and the United Kingdom). The centralised regulatory framework of the United Kingdom allows data analysis on the authorised use of the paint since its restriction up to the present day. This dataset shows a steady decrease in the use of the paint by conservators across disciplines. The paper concludes by considering the professional and ethical implications of lead white paint for artists and conservators, in the context of varied regulation and a decline in use.

Evaluating three water-based systems and one organic solvent for the removal of dammar varnish from artificially aged oil paint samples

A framework was developed to evaluate and compare cleaning systems and cleaning system delivery methods, collectively referred to as varnish removal methods, within art conservation practice. This framework was applied to two water-based cleaning systems, optimised for the removal of dammar varnish from an artificially aged brown earth oil paint, including the surfactant-containing microemulsion, Polar Coating B (from the Nanorestore Cleaning series) delivered via the chemical gel, Higher Water Retention (HWR) (from the Nanorestore Gel Dry series), and a surfactant-free microemulsion delivered via the microfiber cloth, Evolon. In addition, two water-based systems and one organic solvent were used to remove dammar varnish from an artificially aged lead white oil paint sample, including a xanthan gum-stabilised emulsion delivered via a synthetic brush, a surfactant-free microemulsion delivered via cotton swab rolling, and 2-propanol solvent delivered via cotton swab rolling. The evaluation framework was thus applied to two different oil paints, with different sensitivities to cleaning. Through this work, the comparative advantages and disadvantages of the varnish removal methods were demonstrated. Notably, cleaning system compatibility with multiple delivery methods afforded greater versatility, including for reducing unwanted interactions between the cleaning system and oil paint. In addition, a surfactant-free microemulsion proved to be a promising, clearance-free, inexpensive, and modifiable option within current offerings for largely water-based methods for varnish removal.

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.

Non-Invasive Study of the Pigments of a Painting on Copper with the Inscription “Boceto di Pablo Veronese” on the Back

The palette used on a small painting on copper support, with the inscription “Boceto di Pablo Veronese” on the back, was characterized. Non-invasive techniques such as X-ray diffraction (XRD) and hand-held X-ray fluorescence (XRF) were proven to be highly effective for this. The objectives of the proposed work were twofold. On the one hand, the objective was the study, in situ, of the pigments of a painting on a copper support. On the other hand, it was to enrich the literature related to the study of paintings on metal supports, since few related studies are available despite the relatively large number of such 16th and 17th century paintings from Italy and Northern Europe. The results of the analysis showed a copper support with a base layer of gypsum mixed with ochre earths. Atop this layer is a sketch with lead white in the lighter areas and bone black in the darker shadow areas, suggesting that the artist performed a preliminary study of the luminosity of the scene. Finally, the upper or pictorial layer consists of a mix of pigments with some lead white to lower saturation and increase lightness, particularly evident in the flesh tones. The resulting palette thus includes lead white, vermilion, bone black, Naples yellow, and lazurite pigments. These results are compared to Veronese’s other paintings, as well as to those of certain contemporary artists, and the use of the resulting pigments in 16th and 17th century Italian painting techniques is discussed.

Preliminary Study on the Feasibility of Radiation Technique for Mural Protection

Murals are a significant cultural heritage of humanity, and one of the conservation studies is to control the growth of microorganisms. General biocide agents can be used to preserve murals while also providing new organic carbon sources and increasing environmental pollution. In recent years, radiation technology has shown promising prospects for use in heritage protection. Five microorganisms often found in murals were irradiated with an electron beam in this study, and six mineral pigments were tested for color change, Raman spectra and pigment layer cohesion after irradiation. The result showed that irradiation at 20 kGy can basically eliminate Pseudomonas citronellolis, Bacillus sporothermodurans, Streptomyces vinaceus, and Streptomyces griseolus from the culture medium, but only inhibited the growth of Penicillium flavigenum. Lead white pigment showed a color difference of 5.56 (∆E*97) after irradiation, but lead tetroxide, azurite, malachite, ferrous oxide, and cinnabar showed no visible changes. The Raman spectra of the irradiated and unirradiated samples were basically the same. E-beam radiation did not affect the surface cohesion of the pigment layer. This preliminary work shows the potential of electron-beam technology in mural protection and provides basic research and relevant experience for the subsequent in situ mural protection work.

Influence of the addition of crushed glass on the physical and chemical properties of lead white oil paint

Influence of the addition of crushed glass on the physical and chemical properties of lead white oil paint

Forensic examination of a fragmentary funerary portrait in the collection of the Harvard art museums

The Harvard Art Museums’ collection includes six Egyptian funerary portraits of the Roman period. These portraits are all that remains of the funerary equipment of individuals whose bodies were carefully prepared for burial and the afterlife. One example, depicting a man, is particularly complicated, broken into multiple fragments which have been glued down onto a board. The in-depth study of the portrait used a combination of non-invasive techniques, including X-radiography, infrared-, ultraviolet- and visible-induced luminescence imaging, and X-ray fluorescence spectroscopy to identify and locate particular pigments, binders and other artist materials, without needing to take a sample. Targeted sampling, informed by the imaging process, was then undertaken for additional analysis through the use of cross-sections, scanning electron microscopy with energy dispersive X-ray spectrometry, Fourier transform infrared spectroscopy, Raman spectroscopy, radiocarbon dating, and lead isotope ratio analysis. This study identified a core group of three fragments in the center of the portrait that comprise much of the face and neck, tunic, and part of the hair. The remaining 15 fragments contain most of the background, parts of the hair, and the proper left eye and tunic, and are distinct from the central group of fragments. Analysis suggests these fragments were reused from other ancient funerary portraits, and whilst it was not possible to connect any of these added fragments to one another, a potential workshop connection between the central fragments and three added fragments can be suggested based on a study of the composition of the lead white pigment, and similarities in painting technique.

25 Centuries of lead white manufacturing processes identified by 13C and 14C carbon isotopes

Synthetic lead carbonates, cerussite and hydrocerussite, have been used for artistic and cosmetic purposes since Antiquity. Commonly known as lead white, the recipes for the manufacture of this pigment are recounted in many treatises on painting. Depending on the period considered, these two lead carbonates are derived either from a corrosion process or from industrial methods. In both cases, a carbon input, mainly CO2, is necessary to complete the synthesis of this pigment. Its origin depends on the historical period: initially, CO2 came only from microbial activity or the fermentation of organic matter, and from the 19th century on, it was derived mainly from fossil materials. Thus, lead white mainly acquires a 14C and 13C isotopic signature that reflects, to the nearest isotopic fractionation, the nature of the reactants used in its synthesis. In this article, we study the carbon isotopic signature of synthetic lead carbonates by Accelerator Mass Spectrometry (AMS) and Isotopic Ratio Mass Spectrometry (IRMS) through a large corpus of lead whites, composed of reference materials (known manufacturing processes) and of archaeological or museum collection pigments (unknown synthesis). Results show that the 14C content discriminates the manufacturing processes of lead white according to the organic or fossil origin of the CO2 source, and provides absolute dates when pigments are produced by the corrosion of metallic lead in a natural fermentation medium. In addition, δ13C values identify the CO2 source more precisely. This study based on the combination of 14C and 13C data from lead carbonates provides information about the ingredients involved in the synthesis of lead white pigment and demonstrates a good correspondence between the carbon isotopic signature of lead carbonates and the descriptions of lead white recipes in the historical literature.

Hydrogen‑deuterium exchange mass spectrometry to study interactions and conformational changes of proteins in paints

Little is known about structural alterations of proteins within the polymeric films of paints. For the first time, hydrogen‑deuterium exchange mass spectrometry (HDX-MS) was implemented to explore the conformational alterations of proteins resulting from their interaction with inorganic pigments within the early stages of the paint film formation. Intact protein analysis and bottom-up electrospray-ionisation mass spectrometry strategies combined with progressively increasing deuterium incubation times were used to compare the protein structures of the model protein hen egg-white lysozyme (HEWL) extracted from newly dried non-pigmented films and newly dried films made from a freshly made mixture of HEWL with lead white pigment (2PbCO3 Pb(OH)2). The action of other pigments was also investigated, expanding the HDX study with a global approach to paint models of HEWL mixed with zinc white (ZnO), cinnabar (HgS) and red lead (Pb3O4) pigments. The results show structural modifications of HEWL induced by the interaction with the pigment metal ions during the paint formulation after drying and prior to ageing. Both the charge distribution of HEWL proteoforms, its oxidation rate and its deuterium absorption rate, were influenced by the pigment type, providing the first insights into the correlation of pigment type/metal cation to specific chemistries related to protein stability.

Reflectance of Oil Paintings: Influence of Paint Layer Thickness and Binder Amount

Roughness, pigment impurities, and neoformed minerals are important factors affecting the reflectance of painted surfaces. However, other factors that have not yet been studied in detail, such as the total thickness of the paint layer and the amount of binder, should also be considered. In this research, oil painting mock-ups, each made with a different number of layers of paint containing a single pigment (lead white, orpiment, cinnabar, azurite or malachite) mixed with different proportions of oil binder, were examined using a hyperspectral imaging system. The results indicate that these characteristics do not directly influence the reflectance of the painted surface. Interestingly, we found that the distribution of the pigments and the oil binder in the paint system (and pigment-binder interaction) are also key to understanding the reflectance values. Thus, accumulation of oil on top of the uppermost paint layer in the multilayer painting mock-ups caused a reduction in reflectance. The increased translucency of the oil paint containing lead white pigment also modified the reflectance, possibly due to the formation of metal soap. Other factors found to affect the reflectance of the painting mock-ups are discussed.

Time-dependent variation of lead isotopes of lead white in 17th century Dutch paintings.

This study investigates how lead isotopes in lead white pigment can be used as an additional diagnostic tool to constrain the production time of 17th century Dutch paintings. Analysis of 77 well-dated paintings from 27 different Dutch artists reveal significant change in the source of lead used in lead white at the start, middle, and end of the 17th century. Isotopic shifts are related to major historical and socioeconomical events such as the English Civil War and Anglo-Dutch-French conflicts. These observations offer the prospect that lead isotope analysis of lead white could aid attribution and authentication of Dutch 17th century paintings and provide insights into artists’ international travels as well as lead production and trading.

Evaluating the xerophilic potential of moulds on selected egg tempera paints on glass and wooden supports using fluorescent microscopy

• 11 fungal isolates from cultural heritage institutions’ interiors were screened for xerophilic trait. • Specially designed incubators were constructed to hold specific RH levels of 55%, 63% and 74.% • Fungal growth was monitored at low relative humidity on wood and glass supports painted by traditional artists’ paints. • Effects of pigments, support materials and strain variability are discussed. Even though contamination of painted artwork by xerophilic moulds frequently causes aesthetical, physical and/or biochemical biodeterioration, mould growth on paints, prepared from assorted traditional artists’ pigments, has yet to be systematically evaluated especially with regard to low relative humidity (RH) levels and painted support materials. Therefore, we investigated 11 fungal strains isolated mostly from cultural heritage institutions’ interiors for their potential to grow on egg tempera paint films prepared with different colouring agents and applied on wooden and glass supports which were maintained in monoculture in specially designed incubators at three different RH levels of 55%, 63% and 74%. The growth rate of mould over the surface was assessed using fluorescent microscopy after Calcofluor White staining. Additionally, these stains were screened for their xerophilic and hydrolytic potential using standard microbiological assays. Results show that when comparing growth rates on egg tempera paint films, 6 isolates grew exclusively on wood, exemplifying the greater susceptibility of this supporting material to mould attack. Prussian blue paint also stimulated the growth of 6 isolates, and the maximum overall expansion (38%) was observed on Prussian blue painted wood. RH was the key factor limiting growth, and at RH of 55% only a slight growth of 2 isolates was observed on Prussian blue painted wood. On the same samples incubated at RH of 63%, 10 isolates exhibited a moderate to strong growth and 4 of these showed an additional increase in growth at 74% RH. Paints consisting of artists’ pigments carmine lake or lead white in general completely prevented the development of moulds. Nevertheless, tolerance was species/strain dependant and the growths of isolates Cladosporium halotolerans EXF-15,333, Aspergillus niger EXF-14,897 and Aspergillus creber EXF-15,148 on lead white paint (containing ions and salts of heavy metal lead (Pb +2 )) even exceeds 11%. Standard microbiological tests showed that all stains had hydrolytic potential and proved positive for xerophilic trait, nevertheless their ability to develop on egg tempera paint films was mostly dependant of very specific conditions.

Radiocarbon dating of lead white: novel application in the study of polychrome sculpture

Recently, radiocarbon dating underwent considerable technological advances allowing unprecedented sample size downscaling. These achievements introduced novel opportunities in dating cultural heritage objects. Within this pioneering research, the possibility of a direct 14C dating of lead white pigment and organic binder in paint samples was investigated on polychrome sculptures, a foremost artistic expression in human history. The polychromy, an indivisible part of polychrome sculpture, holds a key role in the interpretation and understanding of these artworks. Unlike in other painted artworks, the study of polychromies is repeatedly hampered by repaints and degradation. The omnipresence of lead white within the original polychromy was thus pursued as dating proxy. Thermal decomposition allowed bypassing geologic carbonate interferences caused by the object's support material, while an added solvent extraction successfully removed conservation products. This radiocarbon dating survey of the polychromy from 16 Portuguese medieval limestone sculptures confirmed that some were produced within the proposed chronologies while others were revised. Within this multidisciplinary study, the potential of radiocarbon dating as a complementary source of information about these complex paint systems guiding their interpretation is demonstrated. The challenges of this innovative approach are highlighted and improvements on sampling and sample preparation are discussed.

Lead isotope heterogeneity in lead white: From lead white raw pigment to canvas

The heterogeneity of lead isotope ratios of lead white paints within individual paintings is evaluated. The analyses of five different 17th-century Dutch paintings, sampled in different locations, identifies the presence of isotopic heterogeneity in lead white within a single painting. Pure pigment in the form of cones of 16th-century Venetian lead white, in contrast, was found to be isotopically homogeneous. The study evaluates the origins of the increased heterogeneity of lead isotope ratios in the evolution from the pure pigment to the artwork.

Microchemical analysis of Leonardo da Vinci\u2019s lead white paints reveals knowledge and control over pigment scattering properties

Leonardo da Vinci (1452–1519) is a key artistic and scientific figure of the Renaissance. He is renowned for his science of art, taking advantage of his acute observations of nature to achieve striking pictorial results. This study describes the analysis of an exceptional sample from one of Leonardo’s final masterpieces: The Virgin and Child with St. Anne (Musée du Louvre, Paris, France). The sample was analyzed at the microscale by synchrotron-based hyperspectral photoluminescence imaging and high-angular X-ray diffraction. The results demonstrate Leonardo’s use of two subtypes of lead white pigment, thus revealing how he must have possessed a precise knowledge of his materials; carefully selecting them according to the aesthetical results he aimed at achieving in each painting. This work provides insights on how Leonardo obtained these grades of pigment and proposes new clues regarding the optical and/or working properties he may have tried to achieve.

Insight into the effects of moisture and layer build-up on the formation of lead soaps using micro-ATR-FTIR spectroscopic imaging of complex painted stratigraphies

Metal soaps are formed in paint layers thorough the reaction of metal ions of pigments and fatty acids of organic binders. In this study, micro-ATR-FTIR spectroscopic imaging was used to analyse the formation of lead soaps in oil-based paint layers in relation to their exposure to moisture sources. The investigations were carried out on authentic samples of complex stratigraphies from cold painted terracotta statues (Sacred Mount, Varallo, UNESCO) and different IR-active lead white pigments, organic materials, and lead soaps were discriminated. The saponification of selected paint layers was correlated to the conservation history, the manufacturing technique, and the build-up of layers. The presence of hydrophilic layers within the stratigraphy and their role as a further water source are discussed. Furthermore, the modifications experienced by lead-based pigments from the core of an intact grain of pigment towards the newly formed decay phases were investigated via a novel approach based on shift of the peak for the corresponding spectral bands and their integrated absorbance in the ATR-FTIR spectra. Qualitative information on the spatial distribution from the chemical images was combined with quantitative information on the peak shift to evaluate the different manufacture (lead carbonate, basic lead carbonate) or the extent of decay undergone by the lead-based pigments as a function of their grain size, contiguous layers, and moisture source. Similar results, having a high impact on heritage science and analytical chemistry, allow developing up-to-date conservation strategies by connecting an advanced knowledge of the materials to the social and conservation history of artefacts.

Investigation of proteinaceous paint layers, composed of egg yolk and lead white, exposed to fire-related effects

Fires can have a negative impact on the environment, human health, property and ultimately also on various objects of cultural heritage (CH). This paper deals with an investigation into the degradation of selected proteinaceous paint layers that were exposed to fire-related effects (i.e., fire effluents and/or high temperatures) in a modified cone-calorimeter system. Paint layers of egg yolk adhesive (E) and lead white tempera (E + LW) were exposed to fire-related impacts on top of a CH stack and in a specially designed CH test chamber. On the CH stack, the proteinaceous paint layers were exposed to fire effluents and high temperatures, while in the CH test chamber, the samples were exposed mainly to fire effluents. The molecular changes to the exposed paint layers were analysed by invasive and non-invasive spectroscopic analyses (i.e., FTIR and Raman spectroscopy) and complimented with pyrolysis-GC–MS, while the colour changes were evaluated using colourimetry. It was concluded that the proteinaceous binder degrades into aromatic amino acids and/or fatty acids after exposure to the overall impacts of the fire. Aromatic amino acids were detected by means of the FTIR and py-GC–MS analyses. In the case of the lead white tempera exposure, partial dissociation of the lead white pigment was confirmed by the detection of alteration products, such as lead oxide and lead carbonate. Moreover, the investigation of the E + LW samples exposed for longer times revealed the presence of lead carboxylates. On the other hand, no significant molecular changes were observed with the CH samples exposed to fire effluents in the CH test chamber. The research offered us an insight into the fire-induced effects on selected paints for the first time.