Michael R. Schilling

• MS in Chemistry
• Senior Scientist at Getty Conservation Institute

This investigation provides a meticulous examination of the organic materials employed in the construction of a Qing Dynasty Coromandel lacquer screen housed at the Jinhua Museum in Zhejiang Province, China. Utilizing a combination of analytical techniques, including microscopic cross-sectional observations, systematic layer-by-layer sampling, and...

Asian lacquer is a material that has been used in Asia from ancient times to coat the surface of objects. It is a durable material, but is known to be weak to ultraviolet light (UV). Here, to understand the deterioration characteristics of Asian lacquer due to UV, the changes were analyzed using ultraviolet photometry, IR, and pyrolysis/GC/MS (pyro...

Chinese carved lacquer, lacquer recipes, scientific analysis, pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), historical documents Abstract Carved lacquer is commonly known as diaoqi 雕 漆 in Chinese. It is created from applying multiple layers of lacquer until the...

A collaborative research project between the Getty Conservation Institute and the Walt Disney Animation Research Library investigated storage and conservation treatment strategies for animation cels. Animation cels are transparent plastic sheets inked on the front and painted on the reverse. Common damage observed on aged cels is cracking, loss of...

A collection of studio materials belonging to the Brazilian neo-concrete artist Hélio Oiticica (1937–1980) was analyzed to identify the pigments and binding media present in paint mixtures created by the artist and in Brazilian house, artist, and craft paints. The labels on some of the paint mixtures link them to specific artworks, including Invenç...

In-depth studies of the manufacture and composition of late nineteenth century Korean lacquerware from the Joseon dynasty are underrepresented in the English-language literature. This article, the first to offer a comprehensive layer-by-layer analysis of late Joseon dynasty lacquerware, shows that these objects are made using a mixture of tradition...

The Catholic European presence in 16th-and 17th-century Asia promoted, through trade and missionary activities, the adaptation of indigenous crafts to foreign tastes and needs. One result was lacquered Luso-Asian items. Though variously classified in the past, their inconsistent characteristics called for deeper examination. This paper presents som...

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 difficul...

This work presents a comprehensive, multi-analytical scientific approach for determining the type of lacquer and artistic materials used by Jean Dunand on his work “The Return of the Hunters” (1935). For this purpose, thermally assisted hydrolysis and methylation – gas chromatography/mass spectrometry (THM-GC/MS), optical microscopy (OM) in visible...

This article presents results from a binding media survey of 61 Romano-Egyptian paintings. Most of the paintings (51) are the better-known funerary mummy portraits created using either encaustic or tempera paint medium. Samples from all the paintings (on wooden panels or linen shrouds) were analyzed with gas chromatography/mass spectrometry (GC/MS)...

Pyrolysis gas chromatography/mass spectrometry using tetramethylammonium hydroxide (TMAH) for thermally-assisted hydrolysis and methylation (THM-Py-GC/MS) is a powerful analytical technique for comprehensive characterization of organic materials in European lacquers. A daunting challenge, though, is systematically sorting through the vast number of...

Use of micro-destructive analytical techniques to explore the complex matrix composition, structure and lacquering techniques of multilayer lacquered objects has been the focus of many researchers. This work presents the results of a comprehensive investigation of the “Tixi” carved lacquer micro-sample excavated from Zhejiang province in China (Son...

The long-term behavior of metal stearates used as additive in paints is not well known, and their detection is challenging. This paper presents some aspects of the production of technical metal stearates from stearin in twentieth-century oil paint and its use. Two fast direct analytical mass spectrometry (MS) techniques, evolved gas analysis MS and...

The project examined selected paintings by Edvard Munchs paintings in the Munch Museum (MUM) in Oslo that had been varnished with ketone resins. 23 paintings attributed to Munch (1882–1940) were documented as being varnished with ketone resins between the ‘50s and ‘80s, 16 of them with AW2®.

A lacquered wooden coffin decorated with gilded Sanskrit letters excavated in the Nongso ancient tomb site was constructed around the fourteenth century in Korea. Pyrolysis/gas chromatography/mass spectrometry was employed to identify the materials of the lacquered surface by analyzing the individual layers. The components of lacquer were detected...

Objects made with decorative Asian lacquer are among the most highly prized collections in museums throughout the world. Exposure of Asian lacquer to light causes surface blanching and sensitivity to water and other solvents. This paper presents collective research on the photo-oxidation of Asian lacquer, in which lacquered objects and mock-up samp...

Acceptable air pollutant concentration limits for sensitive artwork are generally at or below a few ppb: this is only ∼1% of the permissible exposure limits for humans. Monitoring pollutants at such low levels is an exceptional challenge, especially to do so in a cost-effective fashion for a large number of locations and microenvironments (e.g., ev...

Wood species identification is important in cultural heritage research because it provides essential information about the materials and techniques used by artists to create objects of art, provides clues to historians about trade routes and guides conservators in the selection of suitable replacements for damaged pieces of wooden objects. Examinat...

This paper presents a novel method for conducting wood identification based on chemical analysis using heart-cut pyrolysis gas chromatography/mass spectrometry (HC-Py-GC/MS) to analyze volatile fractions and thermal decomposition products from finely divided wood samples. This method has several advantages over traditional anatomical identification...

One of the goals of the Preservation of Plastics Project at the Getty Conservation Institute is to investigate preventative and conservation strategies for objects made of cellulose ester plastics. To achieve this goal, several analytical protocols were developed and applied to cellulose ester sculptures, design art objects and reference materials....

Understanding the original techniques in the creation of an artwork is a prerequisite for the selection of the most appropriate conservation method. This is particularly essential in wall paintings where control of potential agents of deterioration and efficient monitoring are limited due to the scale of the paintings and their exposure to uncontro...

The composition of the ancient wax-based painting technique known as encaustic has long been the subject of debate. Ancient sources provide few details of the technology, and modern understanding of the medium is restricted to theoretical interpretation and experimental observation. In this multi-analytical collaborative study, a number of analytic...

Measuring adhesion between heterogeneous samples continues to be problematic for the cultural heritage field, which typically relies on a macroscale destructive tape test method. As an alternative technique, atomic force micros-copy (AFM) is employed in this study to capture nanomechanical information on adhesion from force-displacement curves. In...

More than one hundred samples collected from the V&A Burmese shrine were analysed to investigate the methods of manufacture of lacquer objects from Burma and the structure of the lacquer layers on this particular object, and establish whether there is any difference in the way the main body of the shrine and its decorative elements and satellite co...

Because PU coatings offer a compromise between aesthetic and performance expectations, unachievable with other types of industrial paints, they are currently recognized as the most appropriate option to coat sculptures intended for an outdoor setting. However, the PU class includes various systems, such as two package solvent-borne, two package wat...

Asiarta Foundation and the Getty Conservation Institute have collaborated in research to study Vietnamese lacquer paintings. The primary aim of the project is to gain a deeper understanding of the materials and techniques used in these unique lacquer paintings through technical analysis of various lacquer samples from paintings and from different s...

In order to optimize chromatographic analysis of European lacquer, thermochemolysis temperature was evaluated for the analysis of natural resins. Five main ingredients of lacquer were studied: sandarac, mastic, colophony, Manila copal and Congo copal. For each, five temperature programs were tested: four fixed temperatures (350, 480, 550, 650 °C) a...

Identification of organic materials in Asian lacquers presents many challenges due to their complex formulations and the limited solubility of the main component, which is catechol-rich sap from three species of Anacardiaceae trees that crosslinks to form a hard film. Pyrolysis-gas chromatography–mass spectrometry with thermally assisted hydrolysis...

This paper summarizes the various information that has been gathered in recent years at the J. Paul Getty Museum and Getty Conservation Institute with regard to the organic constituents of Chinese lacquer formulations. While this summary of materials is by no means comprehensive or complete, it captures the current state of the authors’ knowledge,...

Three late-eighteenth-century to early-nineteenth-century objects made from Asian lacquer were analyzed using histochemical staining of cross-sections and pyrolysis-gas chromatography–mass spectrometry, and found to include laccol, and perilla oil and cedar oil, in contrast to urushiol alone, commonly used as an analytical marker for Asian lacquer....

Lacquer has a long and ongoing tradition of use in Asia. Known as qi 漆 in China, its use can be traced back to the Neolithic period and it remains in use today. The earliest known Chinese archaeological lacquered object dates to approximately 6000 bce. Many Chinese classical texts and historical documents over the last 8000 years mention lacquer an...

The meeting of multiple cultures and their mutual influence during the Portuguese expansion in Asia led to the emergence of different types of fusion styles in objects commissioned by the settlers, merchants, and religious orders present in Portuguese India. The east-Asian lacquer coatings of modestly sized wooden objects of various types dating fr...

Oriental lacquer came into vogue in Europe starting from the 16th century. Its immense popularity stimulated craftsmen to imitate these luxury items, using their own familiar materials and techniques. European lacquers are complex, multi-layered coatings, mainly composed of various natural resins. The European Lacquer in Context project focuses on...

This paper focuses on the characterization of materials from fragmented pieces of an imperial lacquer plate in the Luozhuang Han tomb, which dates to the early Western Han dynasty. Various non-invasive and minimally invasive techniques were performed, including optical and electron microscopy, XRF, Raman spectromicroscopy, FT–IR, XRD and THM-Py–GC/...

We isolated a strain of Penicillium chrysogenum from a tomb in Upper Egypt, which was capable of producing brown pigment in vitro when grown in a minimal salts medium containing tyrosine. We present evidence that this pigment is a pyomelanin, a compound that is known to assist in the survival of some microorganisms in adverse environments. We teste...

A collection of 76 synthetic organic pigments was analysed using pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS). The purpose of this work was to expand the knowledge on synthetic pigments and to assess characteristic pyrolysis products that could help in the identification of these pigments in paint samples. We analysed several classes o...

A significant portion of Asian lacquer collections in today's western museums was originally made in China specifically for export to European markets. The J. Paul Getty Museum's collection includes pieces of French furniture dating to the mid-eighteenth century that incorporate panels of Chinese export lacquer as part of their surface decoration,...

Portability of instrumentation, non-destructive spectral acquisition and a wealth of information that can be extracted from the spectra are features that have made Near-Infrared Spectroscopy an attractive topic in the analysis of cultural heritage. In this paper, a classification rule was developed using 41 classes of 535 historical and modern poly...

Cellulose diacetate and cellulose triacetate cels from animated feature films in the collection of the Walt Disney Animation Research Library were tested by several analytical techniques in order to assess their composition and look for evidence of degradation. Triphenyl phosphate and a range of phthalate plasticizers were identified using pyrolysi...

This paper focuses on the chemical and physical characterization of cellulose acetate animation cels from the Walt Disney Animation Research Library dating from 1931 to 2003. The aim of this study is to compare the composition and date of the cels to their degree of deterioration relative to the storage conditions. The chemical composition was inve...

Getty Conservation Institute, USA, has researched into the reproduction of samples of Chinese export lacquer Analysis was carried out on three samples using histochemical staining of cross sections and THM-Py-GC-MS of lacquer layers. Owing to difficulties in removing layer micro-samples, it was not always possible to isolate each individual layer,...

Asiarta Foundation and the Getty Conservation Institute are collaborating in a research project to study the materials and techniques of Vietnamese lacquer painting. The paintings chosen for analysis represent a cross section of works by important Vietnamese lacquer artists working in different time periods and regions of the country. Paint samples...

The 1960s in New Zealand saw a different approach to painting that was linked to an exploration of new materials and ways of using them. New synthetic emulsion paints had become available with properties quite distinct from traditional oils, and many artists chose to use them. Their versatility and ease of use appeared to provide further liberation...

A collection of 30 cans of Ripolin paint in 19 different tints from the studio of Australian artist Sidney Nolan provides a unique reference set for the study of this brand of paint. The cans date broadly to the period 1935–1953. All the Ripolin paints in cans from this study were manufactured at the company's English factory in Southall, London, w...

The detailed characterization of multilayered Asian lacquer coatings is an important task for conservators in order to develop informed conservation and restoration approaches for complex Asian objects equipped with such decorative coatings. Of particular interest is often the identification of organic binders and their distribution within the laye...

This paper presents the preliminary findings from our investigation into the possible microbial origin of brown spots on the walls of Tutankhamun's tomb. GC/MS analysis of the brown spots indicated that they contained 16% (by weight) of malic acid, suggesting microbial involvement in their formation. However, no microbial structures associated with...

Cellulose acetate film plasticized with diethyl phthalate was subjected to artificial ageing regimes and the loss of plasticizer determined by means of Thermogravimetric Analysis and Fourier-transform Infrared Spectroscopy. Alterations in the strain hardening capability of the films was monitored by Dynamic Mechanical Analysis, and the connection b...

The Mogao Grottoes, a World Heritage Site in northwestern China, are located along the ancient caravan routes—collectively known as the Silk Road—that once linked China with the West. Founded by a Buddhist monk in the late fourth century, Mogao flourished over the following millennium, as monks, local rulers, and travelers commissioned hundreds of...

This book is not an art picture book although it contains pictures of works of art, and this is not a scientific treatise although it does include chemical formulae! This book is about both art and science and represents a significant milestone in the journey towards understanding the issues associated with plastics in museum collections, and equa...

Online Field Note, The “Koh S’dech Shipwreck” was found by a local fishing trawler in February 2005 about 20 kilometres off the coast of Koh S’dech, Koh Kong province, Cambodia. Between 2005 and 2006, some 900 pieces of pottery consisting mainly of Maenam Noi (Singburi) storage jars of varying sizes, Sawankhalok, Sukhothai and Si Satchanalai ware w...

Gelatin sizing was a key ingredient during the handpapermaking era. The gelatin concentration in historical papers has never been well documented, however, because measuring the gelatin content required destructive sampling. In this project we developed a non-destructive method using near infrared (NIR) spectroscopy. Gelatin concentrations of 40 hi...

The degradation of pure polymers such as polyethylene, polypropylene, polystyrene and poly(methyl methacrylate) in nitrogen and oxygen was characterized by means of non-isothermal thermogravimetry, chemiluminescence and differential scanning calorimetry. The link between the results of the different methods based on Bolland Gee scheme of polymer ox...

Evolved gas analysis (EGA) using a microfurnace pyrolyzer was shown to be an excellent tool for characterizing polymers and their additives in plastics. In tests of the SamCo, a reference set of plastics produced within the framework of the POPART project, the polymer type was correctly identified in three-quarters of the samples. Moreover, nitroce...

Cellulose acetate, developed about 100 years ago as a versatile, semisynthetic plastic material, is used in a variety of applications and is perhaps best known as the basis of photographic film stock. Objects made wholly or partly from cellulose acetate are an important part of modern and contemporary cultural heritage, particularly in museum colle...

The J. Paul Getty Museum’s collection includes nine pieces of French furniture dating to the mid-eighteenth century that incorporate panels of Asian lacquer as part of their surface decoration. Surrounding the Asian panels, French craftsmen imitated the lacquer surfaces with their own pigments and varnishes to unify the overall appearance of the fu...

The properties of forty naturally aged papers taken from books dating from 1477 to 1793 were assessed using two indicators of paper condition: degree of polymerization and yellowness index. These data were interrelated with three variables that may impact long-term paper stability: pH, gelatin content, and residual metals content. More stable speci...

The J Paul Getty Museum’s collections include several important examples of mid-18th century French furniture that incorporate panels of high quality Asian lacquer into their surface decoration. As part of an ongoing program of technical study of this furniture, scientists from the Getty Conservation Institute are working with conservators from the...

Kinetic evaluation of thermogravimetry data was used to understand the ageing behavior of beeswax used as an artists’ paint medium on ancient mummy shrouds and Fayum portraits. Individual components of beeswax were subjected to dynamic thermogravimetry to assess their evaporation rates, and three methods of kinetic analysis were evaluated for accu...

Issues encountered with dynamic mechanical analysis of artists’ acrylic emulsion paint films are presented alongside modifications to improve controlled relative humidity (RH) experiments using isothermal and thermal scanning conditions. Free films of titanium white (PW6) artists’ acrylic emulsion paints were cast as free films and their viscoelast...

As part of a study of Chumash Indian pigments, some black pigment cakes have been examined. One pigment cake was characterized as soot by polarized light microscopy, and Fourier transform infrared microscopy showed that the binder was proteinaceous. Protein determination was followed by examination using gas chromatography-mass spectrometry analysi...

An extensive study on the effects of cleaning acrylic emulsion paint films with aqueous systems and organic solvents has been made. In particular, the relationship between changes in the paint’s properties and the removal/extraction of surfactant from the surface or bulk of the films has been examined. The methodology involved several analytical an...

After improvements were made to a modified Polymer Labs MkIII DMTA instrument to facilitate repeatable controlled humidity (RH) experiments using isothermal and thermal scanning conditions, the viscoelastic properties of titanium white pigmented artists’ acrylic emulsion films were measured in tensile mode. The effects of temperature, relative humi...

Groupe de Personnages (1938), a canvas painting created in Paris during the Spanish Civil War, required stabilization prior to exhibition. Upon examination, flaking paint and tiny spherical protrusions within those paint layers were identified. A project was initiated to determine materials that could have contributed to the current state of this p...

An ancient Egyptian cartonnage fragment with polychrome decoration was examined to characterize pigments, binder and construction. The fragment, from a broad collar, w as radiocarbon-dated to 512-351 BC. The cartonnage is made on a double layer of plain weave linen, the ground being a mixture of calcite and huntite. The pigment colours employed wer...

This study presents the analytical results of nine paintings executed by Jackson Pollock between 1943 and 1950 in the ‘drip’ or ‘poured’ method for which he is most famous. Pigment and medium analysis reveals that, contrary to popular perception, Pollock’s development of his radical new painting style was not linear. Nor did it involve his immediat...

Alkyd resins, manufactured from polyols, polybasic acids and monobasic fatty acids, may be categorized as oil-modified polyesters. Resin formulators customize the drying and performance properties of alkyd paints either by varying the type and/or stoichiometric proportions of the reactants, or by adding modifiers (for example, styrene, acrylics and...

Technical and analytical studies were carried out on a fifteenth-century German illuminated manuscript, Barlaam und Josephat, in the collections of the J. Paul Getty Museum. Deterioration of the paper support has occurred as a result of interaction with the copper green pigments used extensively for illumination. The green pigment was determined by...

A seventeenth-century sculpture of St Gines de la Jara by Louisa Roldan was technically examined and compared with Francisco Pacheco's seventh-century treatise 'Arte de la Pintura'. The sculpture was found to follow closely but not exactly the recommended practice of polychrome sculpture manufacture. The individual artist's practice was revealed af...

Technical and analytical studies were carried out on a fifteenth-century German illuminated manuscript, Barlaam and Josephat, in the collections of the J. Paul Getty Museum. Deterioration of the paper supports has occurred as a result of interaction with the cooper green pigments used extensively for illumination. The green pigment was determined b...