AIC's 47th Annual Meeting

The Fulbright Scholar Program offers conservators the opportunity of sharing their knowledge and experience in distant lands. In the spring of 2018, under the auspices of the Fulbright Specialist Program, I spent six weeks introducing wooden artifact conservation to the students of the Department of Architecture and Conservation at the Lviv Polytechnic National University, Ukraine. This presentation will focus on my experiences, the little-known aspects of Ukraine’s heritage of wooden architecture and artifacts, and the advocacy for conservation and conservation education that became an integral aspect of my visit. My teaching took the form of nine formal lectures, delivered in Ukrainian, which encompassed a comprehensive introduction to the conservation of wooden artifacts. Visiting Ukraine also permitted me to become aware of the scope and depth of Ukraine's culture, such as the 16-18c vernacular wood churches, known as Tserkvas, some of which were designated Unesco World Heritage Sites.    http://whc.unesco.org/en/list/1424      

Viewing a repository of literally thousands of renaissance and baroque polychrome sculptures, period icons, paintings, furniture, and metal objects was a revelation. These objects and many others require extensive treatment. While visiting Ukraine, I realized that I had to step outside my strict role as a visiting instructor, and to also become an advocate for a Western attitude toward historic preservation and conservation. This advocacy came to include my participation in numerous conferences and meetings, visits and presentations at many institutions, interviews in major publications, and culminated in an address to Ukraine’s parliament. Also, I realized that preserving Ukraine’s cultural heritage would require a new generation of conservators, so I became an advocate for increasing the scientific component of their art conservation education. One aspect of this was co-organizing a tour of the East Coast conservation institutions for my Ukrainian hosts so that upon their return they could upgrade their university’s conservation curriculum and establish a conservation laboratory.  These items and many more details will be the substance of my presentation.

The present study focuses on black resin's composition, beginning and uses. ‏Black resin was used to cover funerary furniture like coffins, shabti statues and boxes, stelae, canopic chests, human and animal statues,‏ and statue bases.  The study utilized gas chromatography-mass spectrometry (GC-MS) to analyze black resin.Black resin is composed of natural resins like mastic, colophony, beeswax, bitumen, and an unknown compound. Natural resin is reported to contain essential oil. Some inscriptions on the tomb of Thebes in Egypt named it sntr , and mastic resin was of high value in Ancient Egypt. Black resin had anti-fungi and antibacterial properties, as well as insect repellents. The sample was taken from a coffin dating back to the Late period to analysis it to know it's composition to choose the best material for consolidation. The coffin, under investigation, was covered internally with a layer of black resin.  

In this paper we discuss the strengthening of methylcellulose (MC) with nanocrystalline cellulose (NCC) and with microfibrillated cellulose (MFC) for high relative humidity (RH). MC is the least hydrophilic cellulose ether among the water soluble ones. Its long-term stability is very high. The same is true of its purity, according to Feller and White (1990). A good tensile strength for re-adhesion of flaking paint on canvas or wood as well as for wood glueing has been proven by many conservators. Therefore the use of MC is becoming more common in the field of conservation. However, the cohesion decreases dramatically when the relative humidity is rising (Debeaufort und Voilley 1997). In the range of 22% RH to 53% RH, the difference in tensile strength was only 9%, whereas for 75% RH the decrease amounted to 46%, for 84% RH even 80%. Nanocellulose has been recently proposed as a novel consolidant for canvas and paper consolidation as well as a reinforcement for some consolidants at room temperature and 50% RH. However, most of our heritage is located in churches, castles, collections or museums without climate control systems. Often the RH is 75%, 84% or even 100%. Therefore we started to strengthen the tested methylcellulose in order to maintain a product more resistant to high RH. After drying, pure NCC and MFC are no longer water-soluble. This is not in accordance with our professional requirements regarding retreatability or reversability. However, the adhesive mixtures MC-MFC/NCC stay water soluble when mixed with methylcellulose. Consequently, mixing the components MC and MFC or NCC could lead to a water soluble yet more resistant adhesive at high RH. Hence we tested the ratio of the components, the preparation, the homogenizing methods (magnetic stirrer, dissolver, SpeedMixer, hand-held blender and ultrasonic), the application, the drying and, finally, the behaviour at high humidities (75% RH, 84% RH and 100% RH). Several analytical techniques were used for the product characterization (tensile strength tests, elasticity tests, weighing technology) as well as scanning electron microscopy (SEM) and atomic force microscope (AFM). Subsequently we analyzed the penetration into porous chalkground on wood by means of fluorescent dyed cellulose and thin sections. The mix of MC and NCC showed the smallest loss of tensile strength during high RH. The tensile strength of the mixture at 75% RH corresponded with the tensile strength of pure methylcellulose at 50% RH. We developed a final product which is substantially more resistant to high humidity than pure methylcellulose and which shows that ratio, homogenizing and application methods are crucial.

The Hispanic Society of America has a small but very fine collection of colonial Spanish American lacquered objects, which are decorated with one of the more widely known indigenous lacquer techniques, barniz de Pasto. The HSA’s objects date from the 2nd quarter of the 17th century to 1800 and were made using native materials and techniques for a European aesthetic which mimicked Asian lacquer and demonstrate the extraordinary craftsmanship of these anonymous artisans whose techniques are still in use today in Colombia. Using only inexpensive and readily available lenses for a smart phone, this study of a mid 17th century barniz de Pasto gourd in the collection will analyze the decorative elements and hopes to identify their sources to show that artisans regularly substituted local flora and fauna in place of the stylized motifs in Asian lacquer as well as incorporating designs from European sources into these ornate objects. Relying on original sources as well as sample analysis conducted on similar pieces, the study will also identify pigments used to create the lustrous effects.

In preparation for the Getty Conservation Institute’s Asian lacquer cleaning project 15 different formulas of Asian lacquer were prepared using laccol, thitsi and urushi. The formulas within the three lacquer categories each differ from the next in the series by one ingredient. This way we will be able to understand how each ingredient affects the behaviour of the surface. Observation and examination of the surface at each stage of the experiment is key to following the changes over time. The Asian lacquer panels were prepared during 2017, by Marianne Webb and Sunhwa Kim, Art and Design Department at Buffalo State College, according to strict protocols to limit differences and ensure standardization of the final products. The three types of Asian lacquer, urushi, laccol and thitsi were obtained from reliable sources. Five formulas of each type of lacquer were produced and all stages were made using the same type of Asian lacquer. Each Koskisen plywood panel was sealed with raw lacquer, and then a ground coat of tonoko and raw lacquer was applied. In the case of thitsi lacquer, bone ash was also incorporated in the formula. Ground coats were polished smooth and sealed with the same lacquer. Test formulas were applied by different means. Urushi and laccol lacquers were applied by brush, however, due to the high viscosity thitsi was applied with a silicone spatula or squeegee. With exception of the roiro urushi none of the coatings were polished after drying. Multimodal imaging: All the samples were documented with different photographic techniques with a modified UV-VIS-IR DSLR camera. Reflected IR and IR-induced IR luminescence techniques were particularly useful in revealing the differences among the different Asian lacquer panels. Surface metrology and multi-scale analysis of the Asian lacquer panels will be introduced and discussed. All 15 panels were investigated using confocal microscopy: Each lacquer panel was examined at 12 distinct areas of interest using a 10x (area 1,600x1,600 μm) and 50x (320x320 μm) objectives. Each magnification shows different physical features to consider. Surface texture can be described by the data reduction techniques of amplitude (height) parameters and spatial parameters. Physical lateral surface features such as peaks and pits and other features at each magnification are also invoked since they are not considered by both amplitude and spatial parameters. The above will be presented in hopes of starting a discussion based on: what identifying features are of interest? Are the features chosen at these magnifications good to define lacquer surfaces? Are the features at these two different magnifications related or relatable in any way? And more.

Constellations II is a thirteen-panel, wooden wall relief designed by Hans Arp (also known as Jean Arp, 1886 - 1966) for Harvard University’s Graduate Center in 1950. One of several artworks commissioned by Walter Gropius and The Architect’s Collaborative for Harvard’s first modernist building on campus, the relief is unique in Arp’s oeuvre as his only large-scale wood relief and his first architectural commission. To prepare for the relief’s display in conjunction with the upcoming exhibition The Bauhaus and Harvard at the Harvard Art Museums, a technical study was undertaken to better understand its condition history and earlier surface appearances, which directly informed treatment and interpretation. Constellations II is a complex case study that offers insight into the working relationship of two prominent art historical figures as well as the challenges of treating a work that was never fully resolved and was removed from its original context. Installed in the Graduate Center’s dining room in 1950 with the title Constellations, the relief originally had a dark red "natural" finish that showcased the graining of the redwood forms. Archival records, photographs, and correspondence between Arp and Gropius indicate that the artist sent instructions to rearrange and modify the relief in 1958 in order to protect the panels from damage and account for viewing obstructions in the room. As part of the revised design scheme, Arp also requested that the panels be painted blue - a compromise between his evolving thoughts on the relief and Harvard’s limited budget for the adjustments. Even after these major alterations prompted the renaming of the relief to Constellations II, drastic changes continued to affect its appearance. By 1975, a series of undocumented painting, stripping, and coating campaigns had taken the appearance from blue, to white, and back to red, leaving the surfaces scratched, patchy, and uneven. Records of these campaigns survive only in sporadic photographs from the 1950s to the 1980s and on the relief itself, where remnants of paint and coatings are present on the edges, backs, and recesses of the panels. It is unclear whether these later modifications were sanctioned by either Arp or Gropius, who both died in the late 1960s, and the motivations behind them are completely unknown. In 2004, the relief was deinstalled from the dining room as part of a larger renovation project and transferred to the care of the Harvard Art Museums. Scientific analysis of the paint and coating layers on the panels helped define a timeline of alterations and corroborate surviving archival documentation, allowing the project team to make an informed decision to return the panels to their original dark red appearance. A digital tool was created to share the past iterations of the relief with the public and to better explain its history at Harvard University. This approach was deemed to be the best compromise to present the relief with an exhibitable surface while respecting the object’s history and the artist’s statements about his work.

The Statue studied here of servant African woman was found before an attempt to smuggle out of Egypt. It is likely that it dates back to the period of Muhammad Ali and his family , this statue is made of gilded wood with black face and decorated with multi colors on gilded layer as a rare technique, In addition, it is designed to rotate 360 degrees. Here we will shed light on identifying the botanical species of wood and the chemical composition of the materials used in decoration. Visual assessment, Optical Microscopy (OM), multispectral imaging technique , SEM-EDAX, X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR) were used in this study to elucidate the components of this statue. The microscopic observation of wood thin sections from several places made it possible to identify the wood used in this statue as pines wood.The analyses provided detailed more information concerning the original materials and the materials added during the previous treatment interventions, which need to be considered when applying a future conservation plan

Making thin sections by hand for microscopic wood identification is a very precise exercise with often frustrating results. Microtomes being out of reach for most private conservators, it is difficult to produce sections that are even, thin, and include all desired information, such as a complete annual ring. Poor sections result in poor analysis, hence the need for a reliable method. This paper explores one such method that has had excellent results. The technique combines a resin (developed for making fish lures and currently also used for forensic analysis), an embedding method for cross-sectional stratification analysis, and sectioning with a simplified microtome. The method has three major advantages over conventional systems: it is fast, inexpensive, and reliable, generating thin sections that are large enough for wood identification. The presentation will delve into several materials and techniques that were explored while developing the method.

Separating the species of Swietenia spp. using traditional wood anatomy has been difficult since the cell structure of all three species is not diagnostic and the color and density overlap. Wood samples were taken from sixteen pieces of 18th C. American furniture made in Rhode Island, all in the collection of the Yale University Art Gallery along with seven samples from the author’s collection. This study compared heartwood chemotypes of 34 samples using Direct Analysis in Real Time – Time-of-Flight Mass Spectrometry (DART-TOFMS) to a known database. Results indicate that all three species of Swietenia spp. can be reliably separated and all three species were found in Rhode Island furniture made in the 18th C.