Bark paintings represent a unique artform that originated in Australia and continues to this day. This paper presents a scientific investigation into both the pigments and binders used by Aboriginal artists from across the Northern Territory (NT) and the Kimberley region in Western Australia (WA) and represents the first major study dedicated to identifying these materials in samples taken from paintings. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), Fourier transform infrared (FTIR) and Raman spectroscopy were used to identify the pigments in the four colors commonly associated with works by Aboriginal artists: red, yellow, black, and white. Iron oxides are used for red and yellow. Typically, kaolin is used for white and carbon or natural manganese ores are used for black, although the use of other pigments such as huntite (white) and battery black were seen in paintings from specific locations. Evidence of trade could not be established during this study; however, analysis shows that artists may use different pigments based on location and availability. A combination of FTIR and pyrolysis-gas chromatography-mass spectrometry (pyrolysis-GC-MS) was utilized to investigate the presence of a binder in the paint. Plant-based materials were identified as the binder in the majority of the paintings. The use of orchid juice was common, both as a preparatory layer on the bark substrate and as a paint binder. The presence of synthetic resins was more widespread than anticipated, attributed to both conservation efforts and more modern painting practices.

Isotopic studies are gaining much interest in heritage science, as they can provide insight into a material's age and provenance. Radiocarbon (14C) dating affords a time frame for the materials being studied, thus providing a historical context, whereas the specific pattern of lead isotope ratios may be used to set geographical constraints on the source of the original materials. Both methods require invasive sampling from the object, and henceforth limits their respective application. With the focus on lead white paint (2PbCO3·Pb(OH)2), in this study we extract the time of production of the pigment from the carbonate anion by radiocarbon dating while its origin is traced by lead isotope analysis on the cation. The methodology was applied to 12 British and 8 Swiss paintings from the 18th to 20th century, with known dates and provenance. The 14C analysis of the lead white in combination with the organic binder and canvas alone places all objects between the 17th and 20th centuries, which is in agreement with their signed date, wheras the lead isotope analysis of all samples are consistent with lead ores from European deposits. In most of the cases the combined results are consistent with the art historical data and prove that isotope analysis is intrinsic to the object. This feasibility study conducted on paintings of known age demonstrates the possibility to maximize the information output from lead white paint, thus increasing the benefits of a single sampling.

Mark Rothko's Harvard Murals are a series of paintings on canvas commissioned by Harvard University and created in the early 1960s. The present study investigates Rothko's creative process, materials, and technique with ultraviolet and infrared imaging, analytical chemistry, cross-sectional analysis, and comparisons with the literature. Infrared and Raman spectroscopy imaging of cross sections help with the chemical mapping of the paint stratifications. A comparison of paper studies, studies on canvas, and the final five works installed give a detailed insight into Rothko's editing process. The intimate relationship between works on paper and canvas is traced by uncovering a back and forth between the two media, and the mixing of dry pigment with binder is a common theme for works on both supports. Motif developments, changes, and distinct painting campaigns become apparent with ultraviolet induced visible fluorescence imaging and infrared reflected infrared digital photography. Color measurements and microfading experiments give insight into the stability and light sensitivity of the materials used by Rothko in the Harvard Murals.

Many Andean textiles are painted, a tradition practiced across the Andes as early as the Lithic period (ca. 10000‒4000 B.C.E). Despite its prevalence and aesthetics, research into painted textile technology is limited. Recently, samples from nine painted Andean textiles were collected from different museums and analyzed at the Getty Conservation Institute in Los Angeles. The samples represent a range of cultures, locations, and times. Analytical techniques included polarized light microscopy and X-ray florescence spectroscopy. Due to the paucity of published data on painted textiles, a comparison is made with mural paintings. Results show that Andean painters used a range of pigments, including ocher and cinnabar, and that pigments were chosen based on their chemical and physical characteristics from at least the Early Horizon period (ca. 950 B.C.E.‒200 C.E.) onward, although there were also cultural preferences for specific pigments. The quality of the cinnabar pigment especially shows that Andean painters had great technical knowledge and skills, superior to what was previously suspected. Patterns of pigment choice and application indicate that painted textiles were primarily produced for funerary purposes.

A treatment with projected light for Mark Rothko's Harvard Murals (1962) is proposed. The group of five paintings on canvas has changed color due to the presence of a fugitive red pigment and excessive exposure to natural light in a room with large windows. For the conservation of Rothko's Harvard room, it is brought into context within his other commissions and environments. The original color of the works is determined by the digital restoration of contemporary photographs. With a camera projector system a compensation image is calculated that is projected onto the original canvas resulting in a restored color appearance. This approach of inpainting with light is compared with considerations of cleaning and inpainting in conventional conservation treatments. Overall lighting and architecture including the unusual wall color carefully chosen by Rothko play a key role in the treatment of the Mural cycle as an environment.

This work presents conservation treatment and analysis of two screenprints on clear plastic, Sandwich and Soda (1964) by Roy Lichtenstein, which is part of the portfolio X + X (Ten Works by Ten Painters). After acquisition, two different pressure-sensitive tapes directly adhered to the printing inks were discovered. At the time of this study, prior attempts to remove tape had resulted in visible damage to the ink. Analysis revealed that the plastic support is polystyrene; the blue printing ink is phthalocyanine blue, the red ink is chrome red, lithol Bordeaux, and barium sulphate; the red and blue ink binder is polystyrene; and the carrier and adhesive components of the tapes are cellulosic material and polyvinyl acetate. Examination and testing combined with extensive scientific analysis enabled thorough understanding of the materials and condition of the prints, as well as successful removal of the tapes and reduction of the adhesive residues.

The megalithic burial monuments are the physical evidence of the social, economical and religious evolution in the Neolithic Era. Their presence all over Europe reveals their significance. They are usually collective tombs and are always located in natural sites. For many years, particularly since the beginning of the 20 th century, the megalithic heritage of the Basque Country, a region of Northern Spain bordering with the South of France, has been subjected to agricultural use, intensive reforestation and other changes that have resulted in various damage and even losses of megaliths. At present a systematic protocol is required to diagnose their condition and set effective intervention processes. The operational goals are the attainment of their legibility, perceptual recognition, physical consolidation and balance with the immediate environment. In the Basque Country and particularly in the province of Biscay, the implementation of this protocol aims to properly recover and value this heritage for its maintenance for the future. Over one third of the ca. 100 megaliths registered in Biscay have been restored. The design of new megalithic routes and promotion programmes has been essential for the public access and conservation of these archaeological sites.

The megalithic burial monuments are the physical evidence of the social, economical and religious evolution in the Neolithic Era. Their presence all over Europe reveals their significance. They are usually collective tombs and are always located in natural sites. For many years, particularly since the beginning of the 20 th century, the megalithic heritage of the Basque Country, a region of Northern Spain bordering with the South of France, has been subjected to agricultural use, intensive reforestation and other changes that have resulted in various damage and even losses of megaliths. At present a systematic protocol is required to diagnose their condition and set effective intervention processes. The operational goals are the attainment of their legibility, perceptual recognition, physical consolidation and balance with the immediate environment. In the Basque Country and particularly in the province of Biscay, the implementation of this protocol aims to properly recover and value this heritage for its maintenance for the future. Over one third of the ca. 100 megaliths registered in Biscay have been restored. The design of new megalithic routes and promotion programmes has been essential for the public access and conservation of these archaeological sites.

The study focuses on the range of pigments and media that the Italian artist Lucio Fontana (1899-1968) employed for selected works dating between 1949 and 1968. Samples were taken from ten groups of works, all on canvas support, as well as from painting equipment that survived in the artist's former two studios. Techniques of analysis used were pyrolysis-gas chromatography-mass spectrometry for media identification, and laser desorption ionization time-of-flight mass spectrometry and Raman microspectroscopy for pigment identification. Fontana's reputation as a daring and experimental artist, best known for his group of slashed paintings called tagli, is seen to correspond with certain unusual material choices he made. The study also points to several links that exist between seemingly unrelated cycles. These links are, among others, based on experiences with in part novel media such as oil, alkyd, polyvinyl acetate, acrylic, acrylic-vinyl, and mixtures of them. With regard to pigments, the selection of samples showed that they were mostly of a synthetic organic nature.

Native American Indian Mimbres vessels from the Classic period (AD 1000-1150) are known for their geometric and figurative black designs on a white background. Owing to the growing popularity of Classic Mimbres vessels among collectors, it is believed that a large number of authentic Mimbres vessels have had their original designs embellished to increase their market value. Typically, the embellishments will enhance a simple central design of an authentic Classic Mimbres vessel to a more complex figurative design. A study was carried out by the Harvard Art Museums, in collaboration with the Harvard Peabody Museum of Archaeology and Ethnology, to investigate the composition of the black, red, and polychrome designs using pyrolysis-gas chromatography-mass spectrometry. Seven of the 25 vessels examined contained critical passages executed in synthetic modern paint media, indicative of deceptive embellishments.

A panel painting of the Crucifixion belonging to the Fogg Art Museum and attributed to an imitator of the 14th-century northern Italian painter Altichiero underwent technical examination to address questions about its authenticity. Suspicions about the painting had been raised on technical grounds and because it was purchased from the famous Sienese restorer and forger Icilio Federico Joni (1866-1946). The materials and technique of the painting were studied and compared to 14th-century Italian panel painting practices and to restoration and forging techniques described by Joni. The examination shows that the distinction between a heavily restored painting and a fake can be ambiguous, particularly when only a vestige of the original remains. The issues raised when dealing with such "renovated ruins," as well as the social context that created an environment conducive to the production and marketing of fakes in Italy in the late 19th and early 20th centuries, are also discussed.

Gaston Lachaise (1882-1935) was one of the principal sculptors working in the United States in the early 20th century, yet his techniques and materials have not been studied systematically. This article presents the results of an investigation of various methods for dating his bronzes that focused on 14 examples in the Fogg Museum, Harvard Art Museums, Cambridge, Massachusetts, and took into account an additional 68 bronzes and 24 models made by the artist. Reconstructing aspects of his artistic process was useful in assigning a relative chronology to several casts. Casting methods and alloy compositions, as well as finishing, patina, inscribed signatures and dates, and foundry marks, also offered important clues for dating. The techniques used in this study were: X-ray fluorescence spectroscopy, cross-section analysis, polarized light microscopy, and Fourier transform infrared spectroscopy. Visual and technical analysis in tandem with documentary research established that 10 Fogg Museum bronzes were lifetime casts and 2 were posthumous, and indicated likely dates for the 2 remaining casts. The investigation provides a basis for further study of Lachaise's bronzes, and contributes to the growing body of technical information about the history of bronze casting in the United States.

Applied tin-relief brocade (commonly called applied brocade) refers to a decorative painting technique using tin leaf applied over a supporting relief mass (filling) which is glued to the artwork to simulate gold and silver textile brocades. This originated in Germany ca 1415-1430 and spread across Europe from the mid-15th century to the mid-16th century. This study focuses on six early 16th century altarpieces in the Basque country in the present province of Guipuzcoa, Spain. Cross sections of the ground and applied brocade were initially examined with optical microscopy and staining tests for proteins and lipids to assess the layering structure and materials present. Further examination with Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy identified the inorganic and organic components of the various layers. Raman spectroscopic mapping was used to image the location of phases in selected cross sections. Five altarpieces from Spain had calcium sulfate grounds, whereas one thought to come from Flanders had a calcium carbonate ground. Raman and FTIR spectra showed that the thick, coarse lower ground layer (yeso grueso) is anhydrous calcium sulfate (anhydrite) whereas the fine, thin upper ground layer (yeso fino) is calcium sulfate dihydrate (gypsum). The filling masses consisted of different mixtures of inorganic (chiefly gypsum or anhydrite but occasionally with other pigments or additives) and organic (protein and/or oil or beeswax) materials. Comparison of the documented historical techniques with the materials found provides insight into local variations of the technique. Copyright (C) 2010 John Wiley & Sons, Ltd.

Three paintings from a group of thirty two attributed to Jackson Pollock (1912-1956) were examined at the Harvard Art Museums Paint samples were examined using Raman spectroscopy scanning electron microscopy-energy dispersive X ray spectrometry (SEM EDX) laser desorption ionization time of flight mass spectroscopy (LDI MS) Fourier transform infrared spectroscopy (FTIR) pyrolysis-gas chromatography-mass spectrometry (py GCMS) and carbon 14 (C 14) dating Carbon 14 dating detected no bomb carbon from atmospheric atomic testing All three paintings contained pigments and media available only after Pollock s death including PR 254 PY151 and an emulsion copolymer of n butyl methacrylate and iso butyl methacrylate

John Singer Sargent's Triumph of Religion at the Boston Public Library, considered to be the artist's masterpiece, is one of the most ambitious mural cycles in the history of American art. This book, comprehensively illustrated, examines and documents Sargent Hall as an art installation (constructed between 1890 and 1919) and describes its restoration history, culminating in the authors' 2003-4 restoration. Sargent (1856-1925) painted the murals on canvas and enhanced their surfaces with relief materials such as plaster, papier mache, metalwork, stencils and patterned cut-outs, jewels made of glass, and Lincrusta-Walton, a corrugated commercial wall covering. During the latest restoration, the three-dimensional elements were removed for the first time, leading to a deeper understanding of Sargent's experimental approach to making the murals and controlling their environment.

I read with great interest Calla Cofield's feature article Underneath the surface (February pp32–35) on art and science. I was one of the researchers who examined the paintings that were attributed to Jackson Pollock, and I believe that she is not entirely correct in her assumption that scientists have yet to learn how to work and communicate with art historians.