A quantitative approach to the study of Asian lacquer surfaces combining non-contact, non-invasive, and non-destructive surface metrology and data science techniques is presented. The lacquers within this artistic tradition-laccol, thitsi, and urushi- combined with various additives possess quantifiable differences in the surface texture/topography that may be used to detect and identify a lacquer type from non-perturbing/contact measurements. This study examined laccol, thitsi, and urushi lacquer handmade test panels with various oils, pigments, and resins before and after aging. Confocal microscopy was used to acquire quantitative surface texture areal data from the test panels and a set of works of art and cultural heritage objects. Data science methods of feature engineering and convolutional neural networks (CNN) were applied to analyze the numerical surface texture data, assign lacquer specimens to the three lacquer types, and quantify the surface changes associated with aging.

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 thermally assisted hydrolysis and methylation pyrolysis gas chromatography / mass spectrometry (THM-Py-GC/MS), the study has provided insights into the complex material composition involved in the fabrication of the screen. The analytical results indicate the presence of multiple organic components within the layers of the lacquer screen. The lacquer film layer was found to contain thitsi, tung oil, camphor, and cedar oil, while the underlying lacquer ash layer comprised urushi, tung oil, and blood. This study presents two important observations that enhance our understanding of the diversity and complexity of lacquer applications in historical Chinese craftsmanship. Firstly, it reports the detection of thitsi in Chinese lacquerware artifacts, a finding that has not been previously documented. Secondly, it identifies an unusual sequence in the lacquer application process, with thitsi found in the outermost lacquer layer and urushi in the foundational ash layer. These observations invite a reconsideration of earlier assumptions about material usage and provide scientific data that may contribute to a more nuanced understanding of the technological variety in ancient Chinese lacquerware.

Lacquered artifacts are among the most exquisite objects in museum collections. However, during aging, a considerable quantity of water-soluble products are formed on the lacquered surfaces, posing significant conservation and preservation challenges. This paper presents in-depth research on the composition of these water-soluble products by the investigation into water extracts from Asian lacquer coatings during artificial aging. Lacquer coatings of 15 specially designed formulations involving different lacquer tree saps (urushi, laccol, and thitsi), drying oils, tree resins and pigments were produced and artificially aged. A set of analytical methods was developed including pH and conductivity measurements, and peak area and index analyses based on gas chromatography–mass spectrometry (GC–MS). Results show that artificial light aging cause the formation of a complex array of hydroxyl carboxyl benzenes (Webboxy products), while simultaneously decreasing the amounts of saturated straight-chain dicarboxylic fatty acids and glycerol. Distinct changes in the average number of hydroxyls and carboxyls bonded to the benzene rings or average chain length of the dicarboxylic fatty acids have also been observed with light aging. The additive that impeded light degradation and formation of water-soluble products the most is drying oil, and the additives that accelerated composition changes of water-soluble products was iron (treatment). Additionally, 12 new compounds have been identified as aging products of lacquer, such as tetramethyl dimethoxybenzene tetracarboxylate and benzene hexacarboxylic acid hexamethyl ester. The understanding of pH and conductivity readings of water extracts from aged lacquer is significantly improved. The research results contribute to the knowledge of aging pathways and mechanisms of alteration to Asian lacquer coatings.

Throughout the twentieth century, the paint industry developed a multitude of new binding media, pigments and additives that improved the appearance, ease of application, and performance of modern industrial paints. Depending on when and where they were first manufactured, and when they were introduced into paint formulations, some of these new paint components could conceivably be chronological markers useful in assigning attribution to specific artists or in the study of forgeries. The aim of this study was to develop a systematic methodology for characterizing organic and inorganic materials in modern paints, and search for potential chronological markers. Colored reference paints manufactured by local companies in Argentina from the 1940s and 1950s were studied with a multi-analytical approach that included Fourier-transform infrared spectroscopy, gas chromatography coupled with mass spectrometry, Raman spectroscopy, X-ray diffraction, X-ray fluorescence and scanning electron microscopy with energy dispersive X-ray analysis. A wide range of compounds was identified due to the complementarity use of the analytical techniques. Historical references, patents, books, and scientific publications about the materials used in that time period provided invaluable information in establishing tentative timelines for modern paint components. This investigation was part of a broader interdisciplinary investigation of Concrete Art, an international art movement of the beginning of the twentieth century, which took place in Argentina and other nearby countries during the 1940s and 1950s. To prove the concept, a micro-sample from “Obra N° 171” by Raúl Lozza was analyzed. Organic and inorganic fractions were studied and the information collected was correlated with developed timelines to support the authentication process. Ultimately, the information from this study may also have a direct impact on the key areas of material characterization, aging behavior, and conservation of works of art made from these products.

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 adhesion, dislocations, and losses of the paint. In practice, flaking paint of animation cels is often removed and repainted rather than consolidated. Being reverse painted, paint consolidation of animation cels adds another layer of complexity to established approaches to paint consolidation. One important component of this study has involved developing minimally invasive treatments for reattaching delaminating paints, which involved studying paint condition, characteristics, and properties. This paper presents recent innovations in paint reattachment that rely on the intrinsic hygroscopic properties of the cel paint formulations. The new treatment is a multi-step approach that manipulates paint properties by using precise levels of relative humidity, established within a humidity chamber, in order to reactivate the paint and reattach it. A major advantage of this method is that a consolidant is not necessary. Method development and a case study procedure are presented in depth. The method developed is effective for cel paints with the same or similar formulations.

A collection of studio materials belonging to the Brazilian neo-concrete artist Helio 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 Invencoes 6, 12, 23, and 34 (1959-1962), and Penetravel 1 (1961), and although the artworks themselves were not available for analysis, Oiticica's methodical journals include paint recipes for these objects. The findings reveal that Oiticica used a relatively narrow range of red and yellow pigments in the mixtures, and the majority of the paint mixtures appear to be oil or oils mixed with alkyds, sometimes with additional additives, including fungicides and extenders. The journal notes are often brief and incomplete, listing only a few paint mixtures for a given work, although many more paint mixtures exist in the collection. These samples, the only physical legacy remaining for much of Oiticica's work that was destroyed in a 2009 fire, offer an unparalleled glimpse into the materials used by this seminal artist and suggest a greater complexity to his works than has thus far been appreciated.

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 traditional lacquerware techniques and materials together with new materials and methods. Through conservation and analysis of four lacquerware objects from the exhibition Mother-of-Pearl Lacquerware from Korea at the Asian Art Museum (29 April-23 October 2016), we identify the materials and techniques used in manufacture and present a new technique to allow conservators to compensate for losses of ray skin inlay. Our discovery that artists used shellac at multiple stages during manufacture calls into question the assumption that shellac was used only as a surface coating. Our findings demonstrate the material and technological complexity of Korean lacquerware from this period and can inform efforts at conservation and analysis of similar objects.

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 (pyrolysis/GC/MS), after exposing the lacquer coating film to UV (λ= 340 nm). In the ultraviolet photometry, the surface exposed to UV showed fluorescence. In IR analysis, the powder sample showed little change after exposure to UV, but on the surface, C = O groups increased, while C―H groups decreased significantly. Analysis with pyrolysis/GC/MS revealed that the composition of organic acid increased significantly. Carboxylic acids having 9 or less carbon atoms and dicarboxylic acids were significantly increased compared to carboxylic acid having 16 carbon atoms. In addition, urushiol with the oxidized side chain was also increased. This shows that the penetration depth of UV is the limiting factor for deterioration, and that the deterioration of lacquer due to UV proceeds with the destruction of carbon–carbon single and double bonds and the subsequent formation of carboxylic acid.

Asian lacquer is one of the earliest natural polymers used in human history. Objects made with decorative Asian lacquer are among the most exquisite collections in museums. This is the first systematic study on the influence of historically used additives on the appearance and morphology changes of unaged and aged lacquer coatings. Macro and microanalytical methods were optimized to investigate the surface changes of lacquer caused by artificial aging. These included visual observation, visible photography, optical measurements (gloss, haze, blanching, macro-texture and color) and microscopy. Results showed that additives altered the transparency, color, and surface roughness and waviness of unaged lacquer surfaces. Aging caused changes in surface morphology, particularly an increase in roughness due to cracking and pitting, and waviness. The transparency of transparent coatings also increased with aging. The widest cracks and earliest formation of cracks with aging were observed for thitsi mixed with wood oil. High surface roughness was observed for aged lacquers treated with iron and for vermillion formulations. A significant reduction in gloss and an increase in blanching was observed for aged iron-treated lacquers due to extensive pitting and cracking. Formulations with vermillion exhibited the largest surface pits, which led to the largest reduction in gloss and the most blanching. Aging caused black spots and darkening of the vermillion pigment. Aged formulations with carbon black exhibited large pits on the surfaces. Analyses of the cracking showed that, to a large extent, the width, length and number of cracks were influenced by components in the formulations. The phenomena of crack closure and displacement were identified for the first time in lacquered objects. The causes of blanching are discussed and the extent of blanching was tentatively quantitatively expressed by gloss and haze data obtained by a goniophotometer. In general, changes in appearance and morphology occurred from the beginning of the light aging cycle, except for cracking. Preventive conservation strategies during exhibition and storage should be tailored according to the formulation and preservation conditions of specific lacquer coatings. This study contributes to the knowledge and conservation of Asian lacquered surfaces. The analytical protocols may also be of value for studying and documenting other coating formulations, and the surfaces of works of art.& COPY; 2023 J. Paul Getty Trust. Published by Elsevier Masson SAS on behalf of Consiglio Nazionale delle Ricerche (CNR). This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ )

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 difficult. Artifacts from museum collections made by bonding transparent PMMA often exhibit a variety of bonding defects and failures not yet addressed in depth in the conservation literature. Therefore, an international project started with the aims of classifying these bonding issues and understand their causes. This paper presents the results of the first part of this project which included the following research activities: surveys of bonding defects in PMMA artworks and design objects in museum collections, a literature review of the most recommended materials and methods used to bond PMMA over time, the preparation of bonded PMMA mock-ups based on literature review, chemical characterization of the bonding materials, thermal ageing of mock-ups, and finally technical examinations of the PMMA bonded mock-ups. The main defects observed in the museum objects surveyed were successfully recreated in the lab and the causes of their formation were assessed. (c) 2020 J. Paul Getty Trust. Publi & eacute; par Elsevier Masson SAS. Cet article est publi & eacute; en Open Access sous licence CC BY-NC-ND (http://creativecommons.org/licenses/by-nc-nd/4.0/).

ê±´ì¡°ì¹ ê¸° ìœ ë¬¼ 세척 시 사용되는 다양한 용매을 대상으로 클리닝 효과를 비교하기 위해 실험을 진행하였다. ê±´ì¡°ì¹ ê³¼ ìžì™¸ì„ ì— 24일 ë ¸ì¶œì‹œí‚¨ ê±´ì¡°ì¹ ì— 물, 에탄올, 아세톤, 헥산을 가하여 ë ¹ì•„ 나오는 물질을 열분해/GC/MS로 검출하였다. 용출되는 양은 아세톤과 에탄올에서 많았으며, 극성이 높은 용매인 물은 ì €ë¶„ìžëŸ‰ 용출에 ë¹„êµì  효율이 좋았다. 비극성 용매인 헥산은 용출량이 매우 낮았다. UV에 24일 ë ¸ì¶œë˜ì–´ 열화가 많이 진행된 ê±´ì¡°ì¹ ì€ ë ¸ì¶œë˜ê¸° ì „ ê±´ì¡°ì¹ ì— 비해 용출되는 물질이 크게 증가하였다. 열화가 되면서 ê³ ë¶„ìž 형태의 우루시올 사슬이 ì ˆë‹¨ë˜ê³ ì‚°í™”ë˜ëŠ” ê³¼ì •ì„ 거쳐 dicarboxylic acid를 포함한 ì €ë¶„ìžëŸ‰ì˜ 극성 물질을 생성하기 때문인 것으로 보인다. 이와 같은 용출 특성은 ì¹ ê¸°ìœ ë¬¼ì„ 클리닝하는 용매를 ì„ íƒí• ë•Œ ìœ ë¬¼ì˜ 열화 상태와 더불어 중요한 ì°¸ê³ ìžë£Œê°€ ë ê²ƒì´ë‹¤. 중심어: ê±´ì¡°ì¹ , ìžì™¸ì„ , 용매, 클리닝, 열분해/GC/MS

건조칠기 유물 세척 시 사용되는 다양한 용매을 대상으로 클리닝 효과를 비교하기 위해 실험을 진행하였다. 건조칠과 자외선에 24일 노출시킨 건조칠에 물, 에탄올, 아세톤, 헥산을 가하여 녹아 나오 는 물질을 열분해/GC/MS로 검출하였다. 용출되는 양은 아세톤과 에탄올에서 많았으며, 극성이 높은 용매인 물은 저분자량 용출에 비교적 효율이 좋았다. 비극성 용매인 헥산은 용출량이 매우 낮았다. UV에 24일 노출되어 열화가 많이 진행된 건조칠은 노출되기 전 건조칠에 비해 용출되는 물질이 크게 증가하였다. 열화가 되면서 고분자 형태의 우루시올 사슬이 절단되고 산화되는 과정을 거쳐 dicarboxylic acid를 포함한 저분자량의 극성 물질을 생성하기 때문인 것으로 보인다. 이와 같은 용출 특성은 칠기유물을 클리닝하는 용매를 선택할 때 유물의 열화 상태와 더불어 중요한 참고자료가 될 것이다.

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 (Vis) and ultraviolet light (UV), and scanning electron microscopy - energy-dispersive X-ray spectroscopy (SEM-EDX) were selected. Furthermore, a novel application of micro attenuated total reflection Fourier transform infrared (µATR-FTIR) spectroscopic mapping by univariate and multivariate analysis was applied for studying the complex lacquer paint stratigraphy. The results show that Vietnamese lacquer was used as a binder, mixed together with linseed oil and pine resins as additives in combination with inorganic pigments, and that shellac was included on the top of the paint; they document an important step in the story of the transfer of Vietnamese lacquer painting techniques to Europe.