UCLA/Getty Conservation Program

A graduate conservation training program focusing on the conservation of archaeological and ethnographic materials


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ANAGPIC 2015, here we come!

Our students and faculty are getting ready to head east to attend the 2015 ANAGPIC conference this week. This year, the conference will be co-hosted by the Winterthur/University of Delaware Program in Art Conservation (WUDPAC) and the University of Pennsylvania’s graduate program in Historic Preservation. This is the first time that UPenn will be hosting ANAGPIC. They, along with Columbia University’s Historic Preservation program, joined ANAGPIC a couple of years ago. The addition of these programs broadens the scope of the papers presented and provides additional opportunities for students and preservation professionals to share information about their recent research and projects.

The UCLA/Getty Program will be well represented with 2 speakers and 4 posters. Abstracts of our program’s presentations are found below. For a full list of papers/posters presented and more information on the conference, you can check out the ANAGPIC 2015 website. And make sure to check out our Facebook page and blog for photos from the conference.


Papers

Torqua Cave: Documentation and Condition Assessment of Catalina’s Rock Images
Tom McClintock

The site of Torqua Cave is a rock shelter on Catalina Island, located 20 miles off the coast of Southern California. The largest of the Channel Islands, Catalina has a fascinating geologic history and is rich in marine and lithic resources. It was was inhabited at least 9000 years BP by the people known today as the Island Tongva. The first documentation of Torqua occurred in the early 1970’s with the identification of 19 red pictographs, although by today’s standards this campaign was not sufficiently systematic. To date there is little to no characterization of the site’s physical history.

This paper presents the results of new imaging technologies based on Decorrelation Stretch and an assessment of local climatic conditions and substrate composition, which will lead to a better understanding of the site’s history and deterioration. Following an assessment of condition, the significance of the site to its stakeholders, including the indigenous population, the island’s contemporary residents and its landowners, will be investigated.

Decorrelation Stretch is a method of producing false color digital images that is able to reveal severely faded pigmented decorative surfaces, which has been used successfully here to identify previously unrecognizable and invisible pictographs. Photogrammetry will be performed to create a unified image of the site, which, at roughly 50’ long and on a hillside, has not been possible to present previously. X-Ray Diffraction has identified the pigment used and the composition of its substrate. Portable x-Ray fluorescence (XRF) spectroscopy and ultraviolet/visible/near infrared (UV/Vis/NIR) reflectance spectroscopy will be performed on-site to create a map of the panels’ surface composition for comparison with visual characteristics such as color variation, patterns of deterioration, presence of water from various sources, and accretions. Polarized light microscopy (PLM) will be performed on a thin-section slide of the host rock’s substrate for identification of its composite minerals. Environmental data loggers will be placed at the site to measure ambient temperature (T) and relative humidity (RH) at the site through daytime/nighttime cycles for a year to compliment spot measurements of rock surface temperature, T and RH that were collected in summer 2014.

This information will be used to characterize the degradation patterns of the bedrock panels that comprise this site, focusing on the interrelationship of the rock’s composition, local climate and water transfer through the rock and from external sources. An assessment of the site’s significant and the danger of anthropogenic impact will lead to recommendations concerning future management strategies and protection.

An Analysis of Unidentified Dark Materials Between Inlaid Motifs on Andean Wooden Queros: Preliminary Findings
Heather White

Paramount in the study of Andean civilizations, past and present, are the people’s rituals and ceremonial customs which have pervaded the Inka and post-Inka periods. These rituals mark social and religious occasions with offerings to the gods that ensure economic prosperity and good health. Decorated wooden cups, called qeros, have facilitated these customs through the centuries, witnessing long use-lives as they are passed down from generation to generation. As custodians of ancient Andean rituals and ways of life, contemporary Andeans use the cups as their ancestors did: to hold and transfer libations of blood or the fermented maize beer chicha, to honor, respect, and celebrate religious, social, and economic activities. It is from here that qeros enter museum collections, their use-life ends, and their preservation as vestiges of Andean culture and ritual begins. In recent years there have been technical studies of Andean qero technology focusing on the materials used for the polychrome inlay decoration, identified as an array of natural and manufactured pigments bound by an organic resin from species of the Elagaeia tree (E. utilis and E. pastoensis), locally known as mopa mopa. However, currently there is a lack of information concerning the dark material(s) present around the polychromy, which exhibits peculiar and substantial loss on vessels in many museum collections, sometimes as though it has been physically scraped off. For this study, different dark materials surrounding the polychrome design on a group of qeros belonging to the Fowler Museum at the University of California-Los Angeles were investigated in an effort to characterize them and potentially explain the technical, cultural, and/or ethnographic reasons for their presence and causes for their loss. Various documentation and analytical techniques were employed, including visual analysis, digital photography, UV-induced visible fluorescence, Reflectance Transformation Imaging (RTI), microscopy, portable X-Ray Fluorescence (pXRF) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and Gas Chromatography-Mass Spectrometry (GC-MS). Preliminary results have shown surface modification and ethnographic wear which appear related to the material’s loss. Identifying this material(s), understanding its origin and explaining its loss will contribute to our knowledge of the vessels’ manufacture and/or ethnographic history and use, and guide our transferred custodianship over such artifacts of Andean traditions.

Posters
Technical study of a miniature Tuareg camel saddle using X-radiography and X-ray fluorescence spectroscopy
Elizabeth Anne Burr

A miniature camel saddle from the Fowler Museum is an example of the dyed leather and metal work for which the Tuareg of Niger are known. This saddle made by Hamidan Oumba for the tourist market is a replica of traditional tamzak camel saddles used by the Tuareg elite. It was suggested by an African art scholar that a miniatures such as this would be constructed using the same materials and techniques as a traditional tamzak with a wooden frame. However, X-ray imaging revealed a substrate that included more dense materials in addition to wood. X-ray fluorescence spectroscopy (XRF) data was acquired from a number of locations over different substrate materials (as corresponding to x-ray images), and different types of dyed leather, which were overlaid for interpretation. Correlations were found between the dense substrate material and the trace elements rubidium and strontium used to identify clays. This and the texture seen in X-ray image suggest that clay based components of the frame were manufactures for this object, a deviation from a traditional construction. Also, the turquoise leather was found to be rich in chlorine, copper, and tin, suggesting the use of bronze chloride corrosion to create the leather pigmentation as is traditional among the Tuareg. These results suggest a combination of both innovation and tradition in the construction of this art piece.

Diagnostic Imaging Techniques for the Identification of Tortoise Shell
Lesley Day

The focus of this poster is the documentation of a specific patterning, found within and unique to tortoise shell, made up of random swirling lines, which most likely correspond to the yearly depositions of keratin that occur as the turtle grows. This phenomenon has been observed in passing in some literature, but has not been fully characterized and is little understood in any discipline. The patterning has been observed as topography in some antique tortoise shell samples, and also as darkened lines in an example that appears to have suffered light damage. This poster will illustrate how documentation techniques including UV-induced visible fluorescence and Reflectance Transformation Imaging (RTI) have proven to be extremely useful in observing and documenting the pattern, and how characterization and further understanding of the pattern can be used as a diagnostic criteria for distinguishing tortoise shell from imitative materials such as plastic and horn.

The documentation illustrated in this poster is one component of my master’s thesis research about light-induced alterations to tortoise shell, and specifically how light may induce alterations to the patterning described, such as darkening and increased visibility. For the study, two taxidermied hawksbill turtles (Iretmochelys imbracata) were generously donated by the US Fish and Wildlife Department of Forensics, and the scutes from one turtle carapace were removed for use as the sample material. The samples are currently undergoing accelerated light aging under three different parameters: exposures mimicking window lighting (which filters some UV), museum lighting (which filters nearly all UV) and a chamber emitting UVA radiation. An important outcome of this research will be a better understanding of photochemically induced alterations in tortoise shell, and preventive lighting guidelines for tortoise shell materials based on the findings of the light aging study.

Piecing together the history of an 18th century printed Armenian Prayer Scroll
Colette Khanaferov

The use of prayer scrolls along with other religious art and literature have for played a significant role in the Armenian culture since the 5th century. The scope of this study is to investigate the history and materials used on a printed, 18th century Armenian prayer scroll. This analysis involves the examination of the scroll with the use of non-destructive analytical photography, fiber optic ultraviolet-visible and near infrared reflectance spectroscopy, X-ray fluorescence and Raman spectromicroscopy. The study attempts to identify and characterize pigments, colorants, ink, and the paper used to construct the prayer scroll. The text along with the illustrations have been translated and studied in an attempt to provide an overall understanding of the scroll, printing techniques, religious significance, use, as well as the traditional practices in the Armenian culture in the 18th century.

Preliminary Research on Biocorrosion of Archaeological Glass
William Shelley

The scope of this research is to investigate the mechanisms and process of biologically induced corrosion of archaeological glass. Archaeological glass samples from Greece and Cyprus suspected to have undergone biocorrosion were analyzed to characterize the chemical composition, microstructure, and topography to determine the difference in the chemistry of the glass surface and the bulk. Analytical techniques included scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray fluorescence (XRF) spectroscopy. Modern glass samples were placed in petri dishes with sulfuric and oxalic acid to simulate potential corrosion from acids produced by microorganisms. This research aims to fill a gap in our knowledge on glass biocorrosion and to evaluate the effects of microorganism on archaeological glass.


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Preventive Conservation Education – Research Topics from the Course “Environmental Protection for Collections” (2014)

Faculty from North American conservation programs who are engaged in instructing graduate courses focusing on preventive conservation strategies for collections are sharing curricula, resources, and topics for student research for the first time. With support from the Getty Conservation Institute and a boost from Prof. Hannelore Roemich at the Conservation Center, Institute of Fine Arts, NYU, faculty and alums met in New York in November 2014 to lay the groundwork for these exchanges. The next meeting will take place just prior to the Association of North American Graduate Programs in Conservation annual meeting in April 2015.

Students in the UCLA/Getty Program in the Conservation of Archaeological and Ethnographic Materials, and students interested in collections stewardship from the Department of Information Studies and other fields, together enroll in a course entitled “Environmental Protection for Collections in Museums, Libraries and Archives.” This course involves students in a review of environmental and biological agents of collections deterioration including light, temperature, relative humidity, pollution, and insects and fungi. Students perform monitoring to identify agents and to gain an understanding of material sensitivities and protective methods available for collections. Of increasing significance within all types of collections are preventive, or passive, rather than interventive, or active, methods of preservation. Collections preservation measures are often designed to limit energy use and therefore also contribute to environmental sustainability. In this course, while research topics are proposed for a required paper, students are encouraged to pursue topics that align with their individual interests. What follows are abstracts of research papers completed by students enrolled in the “Environmental Protection for Collections” class during fall 2014.

Student research projects in preventive conservation from the art conservation programs at Queen’s University and the University of Delaware are also accessible. Research from students in other North American programs, as well as curricula and teaching resources, will eventually be made available online.

Map showing one of the spaces monitored in the course this fall (the archives processing room of UCLA's Biomedical Enigineering Libary) and the types and locations of environmental monitoring equipment deployed (map by Heather White)

Map showing one of the spaces monitored in the course this fall (the archives processing room of UCLA’s Biomedical Enigineering Libary) and the types and locations of environmental monitoring equipment deployed (map by Heather White)

Ellen Pearlstein
Associate Professor, Information Studies and the UCLA/Getty Program in the Conservation of Ethnographic and Archaeological Materials


Exhibition of Daylight Fluorescent Colorants
Betsy Burr

When exhibiting collection material, lighting environment must take into account both the fading properties of material and the lighting parameters required for visitors to read the material on display. This can pose a number of challenges when collection material includes fugitive dyes. When modern daylight fluorescent materials are present, there is an added challenge due to the instability of these molecules and the broad spectrum of light potentially required to fully observe their fluorescing properties.  This poses interesting questions regarding the exhibition environment of these pigments as UV filtration is a common method used to preserve material from fading during exhibition. This raises the question of whether UV filters have a noticeable impact on the readability of fluorescent pigments? What properties must be considered in the safe exhibition and storage of daylight fluorescent pigments?

Fluorescent colorants are found on virtually any substrate as dyes, inks, or pigments within a resin or lacquer, and either applied to the surface or mixed into the substrate as seen in plastics. Daylight fluorescent colorants are added to many products today and have been used within fine art since 1960s pop art movement.[1]  They are also found in modern ethnographic works, particularly laundry “bluing” brighteners applied as colorants to traditional materials.[2] These pigments can be found in collections, and as modern material continues to be accessioned into the future, conservators and museum professionals may find an increasing number of collections material including daylight fluorescent colorants.

 

A Brief Discussion of the Photographic Activity Test and its Relevance to Housing Paper Artifacts
Stella Castillo

The Photographic Activity Test (PAT) was developed by the Image Permanence Institute to explore the suitability of housing enclosures for photographic materials and is specifically a predictor of long-term interactions between enclosures and photographs.  The photographic activity test can be performed on paper or plastic and the results of the test indicate whether the enclosures contain harmful chemicals that will cause image fading or staining over time. The test consists of two components: a test to detect image fading resulting from harmful chemicals in enclosures and a test to detect staining reactions between enclosures and gelatin.   The photographic activity test is now an international standard, ISO18916:2007, and is highly regarded as a selling point by manufacturers of archival and storage products.  According to the Image Permanence Institute, the PAT will assist in the elimination of storage materials that may augment destructive consequences that might arise in a less than perfect storage environment.

 

Traditional methods used to enhance preventive protection of paper-based collections from fungal outbreaks
Lesley Day

One of the most dangerous and prevalent problems encountered in collections of paper-based materials is contamination by mold.  Due to the nutritive properties of cellulose for all fungal species, once an outbreak takes root, it can be difficult to contain.  Historically, chemical fungicides have been used in addition to other methods that can be very hazardous to workers due to their toxicity.  These methods are also increasingly known to be hazardous to the collections they are meant to protect, especially paper.  Fungal species are also known to become resistant to chemical fungicides through adaptation, so it is increasingly likely that they will eventually cease to be effective.[3]  An alternative that has started to gain interest in research for the integrated pest management of cultural heritage collections is the use of natural products derived from plant sources such as essential oils or extracts of their active ingredients, medicinal plants, and spices for use in preventive scenarios that also incorporate other measures such as environmental controls.  Research into their use for remedial treatments is also of interest, though so far it has been difficult to find effective applications that do not put objects at risk. This paper will review the research that has been conducted recently about integrating natural methods into pest management for fungal species, and will evaluate an anecdotal account of traditional Indian practices from an Indian conservator and how these methods might be tested for more widespread use in collections.  In addition to preventing harmful exposure to toxic chemicals for both workers and the collections, these methods could find potential applications for culturally sensitive collections that cannot be exposed to chemicals, anoxia, or other methods that would interfere with the cultural significance of the material.

 

Light Emitting Diodes for Libraries
Mitchell Erzinger

Light Emitting Diodes (LEDs) are semiconductor devices that use electrical currents to produce visible light in the form of photons. LED technology has been advancing in recent years, rapidly outgrowing the traditional incandescent and fluorescent light sources to be one of the most cost and energy efficient light sources on the market. This paper will first examine this research into the efficacy of LEDs, citing studies by the Getty Conservation Institute and the U.S. Department of Energy, and following will be a discussion, involving multiple case studies, of the potential benefits of incorporating LEDs into Library settings.

 

Sustainable Selection and the Costs of Light Sources
Kira Fluor-Scacchi

This paper will address the use of LEDs for exhibition lighting in two cooperative definitions of sustainability; the first is that which supports financial stability for an institution, while the second considers this technology as a component of a system which incorporates a social mentality, the physical equipment, and managerial techniques that encourage an environmentally-conscious preservation model. In order for cultural institutions, such as museums, to ensure their long-term sustainability, exhibition factors must be considered that ensure both the viability of the organization as well as the stewardship of significant objects. Museums house and care for these items, and in turn share them with the local community or a community of researchers who value their preservation and accessibility. Policies must be established to allow artworks and artifacts to be displayed in an environment that is suitable to be viewed by patrons while bearing the costs of their exhibition.

 

The Effects of Temperature and Relative Humidity on Digital Photographic Prints
Karen Karyadi

Since its inception in 1839, the field of photography has continued to evolve both aesthetically and technically. The past few years certainly have seen advancements at an exponential rate in this area, especially with the commercial availability of digital photography. Consequently, digitally printed photographs are increasingly becoming the normative output for photographers and artists working with photographic methods. As such, it is important for museums, archives, and libraries, together with the conservation and photographic communities, to be able to address concerns regarding the storage and display of digital prints as part of their role as cultural institutions. Indeed, technological developments in digital photography are taking place on a daily basis and will continue to do so into the foreseeable future—an ongoing shift that must also be anticipated and take into consideration. Nevertheless, this paper focuses on the effects of temperature and relative humidity on digital photographic prints, particularly within the context of cultural institutions.

 

Protecting museum objects from pest infestation and biological growth
Colette Khanaferov

As a visitor it may be hard to conceptualize external factors that can effect a museum’s collection. A museum’s responsibility for the object begins once the object has been acquired into the collection. Conservation of an object however is not limited within the walls of the conservation lab but needs to be considered throughout the entire museum space. Once in the museum, objects are susceptible to pest infestation, biological growth, and deterioration due to fluctuation of temperature and humidity. The scope of this paper is to discuss previous and current approaches taken to eradicate pest infestation and biological growth as well as introduce a potentially new and safer alternative. Chitosan is a naturally occurring polysaccharide that is produced from chitin and can be found in many organisms such as crab shells and shrimp. The use of the polymer includes applications in the food industry as antibacterial agents, in the pharmaceutical field for drug delivery systems as well as new medical advances. Chitin and chitosan can be useful in the conservation field for object preservation.

 

The Physical Implementations in Preserving Fashion Forecasting Reports
Alexander Kosztowny

Archivists, librarians, and historians desire to document, save, and preserve the past. Some ephemera, like newspapers, have an original intent that was not meant to last long periods of time, yet these items are kept and preserved to the best of archivists’ and preservationists’ abilities. One other such example is trend forecasting books and predictive reports. These books are used by the fashion industry to predict what silhouettes, colors, fabrics, and styles will be the most popular in upcoming seasons so designers, manufacturers, and retailers can successfully sell items that consumers want. There is a need to preserve these books in terms of their documenting costume history, popular and street culture, and how the fashion industry has evolved from an elusive, designer based industry to a global communication of style, technology, and individualism. There are many concerns when physically preserving these books that are not unique or unrelated to the preservation of other artifacts and books. However, due to the multimedia nature of trend forecasting reports, many considerations must be taken into account.

 

Illuminative Inhibition of Microbial Growth in Cave Art Systems
Tom McClintock

Several cave systems in France and Spain house some of the earliest known examples of painted surfaces in the world, and since their discovery have attracted major public interest and visitation. The environments of these caves are extreme, characterized by nearly total darkness, stable temperatures, high relative humidity and low amounts of organic nutrients. The organisms that are able to survive in these conditions are highly specialized, and the ecosystems they comprise are subsequently susceptible to change. In this regard, no development of hypogeal environments to accommodate tourism can be considered minor, although the obvious examples of excavation, construction of pathways (even elevators) and installation of air conditioning systems were common practice. When one considers that Lascaux, in Southern France, and Altamira, Spain, two of the most extraordinary cave art sites in the world, hosted respectively 1,800 and 3,000 people per day at the zenith of their visitation[4], [5], the irreversible effect on these delicate systems is hardly surprising. Both Lascaux and Altamira suffered the misfortune of being discovered before management, preservation and scientific communities with an enlightened understanding of these deleterious effects existed, and they must all now play catch up to mitigate the sites’ deterioration.

 

Making Change in Environmental Requirements for Museum Loan Policies
Hilary McCreery

Museum loan policies exist, in part, as a way for museums to ensure that the materials that are loaned out to other institutions will be cared for properly and will return in the same condition in which they departed. One important facet of museum loan policies is the set requirements for museum environments, which establish, among other specifications, explicit levels of temperature and relative humidity to be maintained by the borrowing institution. However, there are many differing perspectives on best practice for implementing standards for museum environments, many of which are based on historical research findings and experience. In fact, “over the past 100 years, both research and practice in the area of environmental standards for storage, loan, and exhibition of museum collections have produced rather bewildering results, from oversimplified formulas to complex, yet incomplete research findings” (American Institute of Conservation, n.p.). Currently, there continues to be much discussion in regards to the rigid parameters set for museum environments, especially in the context of loans, and some conservation and museum professionals have begun to call for a change toward not only more flexible environmental standards, but more transparency on the part of museums about their current practices. As a result, the International Institute for Conservation of Historic and Artistic Works (ICC) in collaboration with the International Council of Museums Committee for Conservation (ICOM-CC) recently released a declaration for new environmental guidelines, which promotes both transparency of and flexibility for environmental conditions in loans policies. While the tight parameters established for environmental conditions in loan requirements have historical roots, the debates taking place in the current landscape of museum policy have called for these new changes in international standards.

 

Bentley’s Medicinal Plants: A Recommendation for Exhibition
Katherine Monroe

Spices, Exotic Flavors & Medicines, a digital exhibition put on by the History Special Collections section of the Louise M.  Darling Biomedical Library at UCLA, incorporates digitized  images  of  the  four  volumes  of  Robert  Bentley  and  Henry  Trimen’s  Medicinal Plants; being descriptions with original figures of the principal plants employed in medicine and an account of the characters, properties, and uses of their parts and products of medicinal  value (hereafter  referred  to  as  Medicinal Plants).[6]  With such an interest in the Internet exhibition,  demand  for  a  twelve month  physical  exhibition  of  the  volumes  has  arisen, leading to an examination of the public reading room in which they are to be displayed, as  well as of the volumes themselves.  The results have led to the following observations and recommendations,  with  the  desire  to  successfully  exhibit  the  four  books  without compromising their preservation.

 

The Use of Experimental Lighting on Archaeological Sites to Prevent Microbial Growth
William Shelley

Microorganisms have the ability to affect archaeological sites not only aesthetically, by covering surfaces with different colored ‘patinas’, but also chemically by producing corrosive acids that attack surfaces.  Methods in the past to control and reduce the growth of microorganisms have included their removal mechanically and the use of biocides.  These techniques however are intended only to remove existing growth and will not prevent future growth.[7]  The use of biocides can be detrimental to archaeological sites if they are not completely rinsed away and leave residues on surfaces.  Biocides may also be toxic to the individual who applies the material, as well as to the environment.  Recently, new strategies to control the growth of biological activity on archaeological sites have been developed using specific wavelengths of light.  A brief overview of previous work on the subject and a discussion about their potential use follows.

 

Environmental Considerations for Alternative Building Materials Used in Museum Storage and Display
Heather White

The materials used for the storage and display of collections play a vital role in maintaining the condition of the collection. Experience has shown that more often than not, traditional building materials contain components that will off-gas harmful vapors, like volatile organic compounds (VOCs), which can initiate or accelerate degradation processes in susceptible cultural materials. Such reactions are promoted by their use and decomposition, especially when subjected to various indoor climate variables. The “indoor chemistry” of building products has been studied in depth, and accounts for reactions that happen during the production of the material whose products are released at the customer’s site, or synergetic reactions between different materials at the site once installed.[8],[9]

Alternative building materials like aluminum composite materials (ACM), entered the market addressing these concerns and offering an inert construction material safe for indoor environments and the collections held within them. However, the question arises: Can such materials so carefully manufactured to be lightweight, strong, weather resistant, water proof, heat resistant, fire resistant, formable, nitrogen/chlorine/sulfur-free, with low VOC emissions, also be safe for the environment at large in terms of their manufacture and disposal? Further, are corporations spearheading the fabrication of safe and archival exhibition cases, like The Small Corporation, maintaining environmentally conscious objectives in their manufacturing processes?

 

Footnotes
[1] Margaret Holben Ellis, Christopher W. McGlinchey, and Esther Chao, “Daylight Fluorescent Colors as Artistic Media,” in The Broad Spectrum (London: Archetype Publication Ltd, 2002), 160–67.

[2] Nancy N. Odegaard and Matthew F. Crawford, “Laundry Bluing as a Colorant in Ethnographic Objects,” in ICOM Committee for Conservation, 11th Triennial Meeting in Edinburgh, Scotland, 1-6 September 1996: Preprints (James & James (Science Publishers) Ltd., 1996), 634–38.

[3] Shaheen Fauzia. 1995. “Application of Kanja Seeds (Pongamia glabra vent) for the control of Museum Insects.” In Biodeterioration of Cultural Property 3: Proceedings of the 3rd International Conference on Biodeterioration of Cultural Property, July 4-7, 1995, Bangkok, Thailand, (Office of Archaeology and National Museums. Conservation Science Division, 1995), pp. 567-575.

[4] Bastian, Fabiola, et al. “Impact of biocide treatments on the bacterial communities of the Lascaux Cave.” Naturwissenschaften 96.7 (2009): 863-868.

[5] Schabereiter‐Gurtner, Claudia, et al. “Altamira cave Paleolithic paintings harbor partly unknown bacterial communities.” FEMS Microbiology Letters 211.1 (2002): 7-11.

[6] The digital exhibition can be accessed at http://unitproj.library.ucla.edu/biomed/spice/index.cfm; Robert Bentley and Henry Trimen, Medicinal Plants; being descriptions with original figures of the principal plant employed in medicine and an account of the characters, properties, and uses of their parts and products of medicinal value (London: J. & A. Churchill, 1880) .

[7] Koestler, R.J., Koestler, V.H., Charola, A.E., Nieto Fernandez, F.E. (Eds), 2003. Art,Biology and Conservation: Biodeterioration of Works of Art. The Metropolitan Museum of Art, New York.

[8] Uhde, E., and T. Salthammer. “Impact of reaction products from building materials and furnishings on indoor air quality—A review of recent advances in indoor chemistry.” Atmospheric Environment 41 (2007): 3111-3128.

[9] Satlhammer, Tunga. “Emissions of Volatile Organic Compounds from Products and Materials in Indoor Environments.” The Handbook of Environmental Chemistry 4, Part F (2004): 37-71.


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UCLA/Getty Program Welcomes Visiting Scholar Dr. Guofeng Wei

The UCLA/Getty Program welcome visiting scholar Dr. Guofeng Wei, who will be working with us through January 2016. Dr. Wei comes to us from the Department of History, Anhui University, China.  He received his Ph.D. in Scientific History and Archaeometry from the University of Science and Technology of China. His current research focuses on the recipes and crafts of historical lime mortars of China, as well as a study on the application of traditional stick rice-lime mortar in conservation of cultural relics.  More recently, he carried out research studying the trace element characteristics of copper prills in slag from Tangjidun sites of copper smelting dating back to the late Shang Dynasty (ca. 1300 BC) in Anhui Province.  In addition he is studying the casting technology of bronze vessels dating from the late Shang Dynasty to Spring and Autumn Period (ca. 1300BC – 470 BC) from Zongyang County.

Dr. Wei will be providing lectures for some of our programs courses, as well as conducting his own research while he’s here.  He is currently giving two lectures on ancient metallurgy and metal casting in the course Conservation Laboratory: Metals II  (CAEM 239).

Dr. Guofeng Wei


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RTI of Etruscan Bucchero Fragments at Poggio Colla

My first summer internship with the Mugello Valley Archaeological Project (MVAP) at Poggio Colla has wrapped up, and it was an incredible season with exceptional finds! Under the guidance of head conservator, Allison Lewis—a UCLA/Getty alum (‘08 )—and with the sponsorship of The Etruscan Foundation’s 2014 Conservation Fellowship, I was afforded the amazing opportunity to participate in this project, which has been underway for the last several decades. MVAP has significantly contributed to the study of ancient Etruria with their work at Poggio Colla, the site of a hilltop settlement and sanctuary that spanned the 7th-2nd centuries B.C.E.

A particularly groundbreaking find happened in 2011, when a student participating in the MVAP field school found a stamped bucchero fragment that appears to depict a woman in the midst of childbirth. This imagery is the earliest documented in Italy and nearly unparalleled in the ancient Mediterranean, however study of the finely recessed scene is difficult due to its small size and worn nature. It takes just the right angle of raking light to highlight the surfaces and make the scene legible (Fig. 1), which is often the case with these stamped and incised bucchero vessel fragments.

Fig.1. The birthing stamp (inv. PC 11-003), found on a bucchero fragment, measures just around a centimeter in height and is worn, requiring magnification and raking light to study its imagery. [Photos courtesy of Dr. Phil Perkins, The Open University].

Fig.1. The birthing stamp (inv. PC 11-003), found on a bucchero fragment, measures just around a centimeter in height and is worn, requiring magnification and raking light to study its imagery. [Photos courtesy of Dr. Phil Perkins, The Open University].

As an 2014 Etruscan Foundation Conservation Fellow, I proposed a special project to the Foundation involving the documentation of bucchero fragments using Reflectance Transformation Imaging (RTI), which Allison has wanted to test at Poggio Colla for several field seasons. This technique, created by Cultural Heritage Imaging (CHI), involves a low-cost, easy photographic set-up that can be macgyvered in the field with fairly basic supplies (Fig. 2). RTI essentially blends a series of photos of an object under different angles of light to create an interactive file (a polynomial texture map) that one then explores using a “virtual torch” in various rendering modes. In other words, instead of researchers straining their eyes and handling the object in different raking light or studying static images, they can explore the features and subtle details of the object’s surface in a single, high-resolution image with an adjustable light source that they can control.

Fig. 2. We were able to disassemble a standard desk lamp to become our movable light source, much to our excitement! This imaging technique was affectionately called “A Thousand Points of Light” amongst the staff, and it was pointed out that it’s quite a ritualistic process (appropriate for the sanctuary site) as we huddle on the floor around an ancient artifact with a single torch lighting us.

Fig. 2. We were able to disassemble a standard desk lamp to become our movable light source, much to our excitement! This imaging technique was affectionately called “A Thousand Points of Light” amongst the staff, and it was pointed out that it’s quite a ritualistic process (appropriate for the sanctuary site) as we huddle on the floor around an ancient artifact with a single torch lighting us.

Our set-up was simple. We picked a relatively closed-off room adjacent to the field conservation lab where we could have good control over ambient light; as you can see, it doesn’t have to be a special room-nor a room at all if you’re on-site! We used the lab’s point-and-shoot Canon G10 digital camera with a remote so as not to shake the camera when capturing the images, a copy stand, a disassembled desk lamp that we tethered to a string, and small, black reflectance spheres purchased by the conservator prior to the season (Fig. 2).

The black spheres are required in the frame near the object, in order to reflect the location of the light source for the software during image processing (Fig. 3). Any black, reflective sphere can be used; Allison purchased 1/4” and 7/16” silicon nitride (Si3N4) ceramic balls used for ball bearings (Boca Bearing Company), which we mounted in frame with Benchmark wax, at times stuck to bamboo skewers to be held level with the object’s surface. The string tied to the lamp was measured to roughly 4x the diameter of our object, becoming the fixed radius at which we moved the light around the object for each photo (Fig. 2).

Fig. 3. Items inserted in frame for image processing or posterity (such as the black spheres, grey scales, or labels) can be cropped out in the final stage of processing in RTIBuilder so that your final product is simply your subject, to be navigated and explored in RTIViewer.

Fig. 3. Items inserted in frame for image processing or posterity (such as the black spheres, grey scales, or labels) can be cropped out in the final stage of processing in RTIBuilder so that your final product is simply your subject, to be navigated and explored in RTIViewer.

Keeping the camera in a stationary position with our object and black spheres in focus, we proceeded to take around eighty images per object, with each object taking roughly fifteen minutes to shoot; one person snapped the photo while the other moved the light. We continued taking photos until we felt we covered a full “umbrella” of light around the object in our series of images.

The photos were then processed using the RTI software (RTIBuilder), which is available for free on CHI’s website, along with RTIViewer for navigating the final product. RTIBuilder can be finicky and particular, especially in naming files. No spaces, hashtags or other similar characters are acceptable in file names. We also found that the program did not recognize capitalized file extensions (for example not .JPEG files, only .jpeg) so if you can’t control which file type you’re capturing in on your camera, you’ll need a computer with Photoshop or an equivalent image processing software that can convert them. For optimal quality, CHI recommends capturing images in RAW and then converting to jpegs (RTIBuilder can only process jpeg files). Processing items inserted in frame (black spheres, gray scale, label, etc.) can be cropped out at the end before the images are converted into the single digital file, which can be interactively viewed by anyone who has downloaded the free RTIViewer (Figs. 3-5).

Fig. 4. When you open RTIViewer, you have several options at your disposal: you can control your light source; you can zoom in and out on your subject and move around over its surface; you can take a snapshot of your field of view (which saves as a .jpg and XMP file); and you can play with a diverse range of rendering modes available in the dropdown menu.

Fig. 4. When you open RTIViewer, you have several options at your disposal: you can control your light source; you can zoom in and out on your subject and move around over its surface; you can take a snapshot of your field of view (which saves as a .jpg and XMP file); and you can play with a diverse range of rendering modes available in the dropdown menu.

Fig. 5. The different rendering modes can emphasize or deemphasize particular surface characteristics, and some modes allow you to study the surface without the distraction of surface pigment/colors.

Fig. 5. The different rendering modes can emphasize or deemphasize particular surface characteristics, and some modes allow you to study the surface without the distraction of surface pigment/colors.

As you can see, this imaging technique offers a different, versatile way of studying the morphological and topographic features of an object’s surface, no matter how minute, without the need to access the object itself. Given the various rendering modes available in the RTIViewer, it can be used as a supplementary tool in examining the object, and it can also be offered as an alternative format for researchers wanting to study the piece, limiting unnecessary handling….which we conservators like to hear! We found RTI to be an especially useful field tool for recording and studying worn, stamped bucchero decoration, fabrication related marks on bucchero surfaces, and incised characters on ceramic and stone surfaces (Figs. 6-8). After a great pilot program, the MVAP conservation staff and other project members hope to continue exploring its potential applications at Poggio Colla in future seasons.

Fig. 6. An incised and stamped bucchero sherd (inv. PC 13-075).

Fig. 6. An incised and stamped bucchero sherd (inv. PC 13-075).

Fig. 7. A bucchero sherd (inv. PC 14-062) with reticulate burnishing, nearly invisible under even light (note the ‘Default’ image). Modes like ‘Normal Unsharp Masking’ can reveal the very subtle, recessed burnishing marks, and others like “Diffuse Gain’ can contrast them.

Fig. 7. A bucchero sherd (inv. PC 14-062) with reticulate burnishing, nearly invisible under even light (note the ‘Default’ image). Modes like ‘Normal Unsharp Masking’ can reveal the very subtle, recessed burnishing marks, and others like ‘Diffuse Gain’ can contrast them.

Fig. 8. An inscribed stone base (inv. PC 05-105).

Fig. 8. An inscribed stone base (inv. PC 05-105).

Heather White (’16)


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Class of 2014 internship and thesis presentations

The quarter ends next week and that means our 3rd year students are back to give their final presentations before graduation.  Today they’ll be presenting on the work they did during their 3rd year internships as well as on their MA thesis projects (listed below).  Afterwards, it’s time to celebrate their graduation!  We’re very proud of the class of 2014 and wish them the best as they start their careers as conservators!

  • Brittany Dolph-“Experimentation with and evaluation of ethyl silicate-based group formulations for potential application to weather and/or porous silicaceous stones”
  • Ayesha Fuentes-“Technical examination of ritual bone ornament ensemble from Himalayan Region with notes on treatment and handling”
  • Geneva Griswold-“Treatment of a Tuscarora headdress:  Consultation and material selection”
  • Caitlin Mahony-“Examining two novel consolidants for the treatment of powdering leather suffering from the acidic deterioration commonly referred to as ‘red rot'”
  • Casey Mallinckrodt-“The technical analysis of an ancient Egyptian/Ptolemaic sarcophagus lid from the collection of the San Diego Museum of Man”
  • Madeleine Neiman-“The alteration of cinnabar in archaeological Roman wall paintings”
  • Alexis North-“Biomimetic hydroxyapatite as a new inorganic consolidant for archaeological bone”
  • Carinne Tzadik-“Conservation, analysis and treatment of Jaina figurines”
Class of 2014 on the day of their final presentations posing in front of a photo taken of them when they started the program back in 2011.

Class of 2014 on the day of their final presentations posing in front of a photo taken of them when they started the program back in 2011.


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Examining Plant Fibers and Identifying Characteristic Features using Microscopy

Last quarter in the class Structure, Properties and Deterioration of Organic Materials (CAEM 262), we completed practical assignments in order to understand how to identify and approach organic materials found within and comprising cultural objects.  Each week the class studied a different category of organic materials including wood, paper and bark cloth, other plant materials, skin and leather, bone and ivory, plastics, and hair, quills and feathers.

During our study of plant fibers, we utilized light microscopy, both with transmitted and polarized light, to view and identify fibers and diagnostic features of plants that could help in identification and documentation of materials used in the manufacture of objects.  Different types of plant tissues and fibers can be used to produce a range of materials including cordage, baskets, paper, and native or conservation mends.  The processing method of fibers may also be seen, and commercial fibers can usually be identified by their absence of impurities or extraneous material.   An important reason for identifying plant materials is to understand their current state and how they may deteriorate in the future due to their inherent properties. By studying and identifying the materials of which an object is made, as conservators, we will be to make more informed decisions about conservation treatment, repairs, stabilization and storage (Florian et al. 1990: 29).

Using the UCLA/Getty Program’s vast reference collection of plant materials, each student chose and mounted on a microscope slide a surface section of a seed hair (fibers that surround plant seeds, like cotton or kapok), a surface section of a bast fiber (fibers harvested from woody stems, like flax or hemp), a cross-sectional sample of a monocot leaf (like palm) and a cross-sectional sample of a monocot stem (like a grass).  We then took photomicrographs of our samples and labeled the features that could be identified.  Features that we were hoping to observe included tissue organization, cellular structure and details, and birefringent patterns and colors.   Below are the photomicrographs obtained using and Olympus BX51 microscope with transmitted and cross polarized light by Lesley Day, William Shelley and Betsy Burr.

 

Seed Hair Surface Sections

Polarized Light Microscopy (PLM) is very useful in identifying cotton and other seed hairs.  Cotton characteristically shows ribbon-like twists and birefringence.  Cotton hairs are single cells that originate from the fruit or boll of the cotton flower.  Other seed hairs such as kapok and cattail characteristically show few to no features, and lack of features can help in their identification (Florian et al. 1990: 40). Samples were prepared by teasing out a small amount of material and placing it on a glass microscope slide.   A drop of water was placed on the fiber and covered with a plastic cover slip.

Image: Lesley Day

Image: Lesley Day


Image: William Shelley

Image: William Shelley


Image: Betsy Burr

Image: Betsy Burr

Bast Fiber Surface Sections Bast fibers are long thick-walled cells harvested from the inner bark of hardwood trees.  They are commercially and culturally important because they are used in cordage, basketry and paper.  Flax and hemp are examples of bast fibers and are harvested from the stems of dicots.  Salient features used to identify bast fibers are dislocations (also called kinks), long length, tapered ends and narrow lumens.  The fibers usually occur as clusters, and the presence of single fiber ultimates may indicate more extensive processing (Pearlstein, lecture 28 January 2014). Samples were prepared in the same manner as above.  In some instances, the samples were macerated in order to separate fiber bundles for better viewing of fiber ultimates, by gently applying pressure in a circular motion to the coverslip with a pencil eraser.

Image: Lesley Day

Image: Lesley Day


Image: William Shelley

Image: William Shelley


Image: Betsy Burr

Image: Betsy Burr

Cross Sectional Sample of a monocot leaf Monocot leaves from palms and grasses are commonly used culturally in the weaving of baskets and other structures.  The leaves are quite strong due to the parallel veins and the strengthening sclerenchyma and vascular bundles corresponding to them.  A waxy cuticle is present on the exterior, which contains natural, water repellent waxes, and is often removed during processing.  Observable characteristics of monocot leaves include the epidermis, vascular bundles (which include xylem and phloem cells), sclerenchyma bundles, and occasionally stomata, which are tiny mouths that permit transpiration (Pearlstein, lecture 28 January 2014)! Samples were prepared by cutting a very thin slice from the end of a monocot leaf using a scalpel and carefully placing the sample on a glass microscope slide so that the cross section faced up. Once the sample was in the correct orientation, a drop of water was placed on the area around the sample and a plastic cover slip was placed on top.

Image: Lesley Day

Image: Lesley Day


Image: William Shelley

Image: William Shelley


Image: Betsy Burr

Image: Betsy Burr

Cross-sectional sample of a Monocot Stem Monocot stems are also used in basket weaving and stems are obtained from grasses, sedges, rushes, and palms.  Monocot stems do not develop bark on their exteriors and do not exhibit growth rings. Identifying features observable in a cross-sectional sample include the outer cortex, vascular bundles (in which phloem, xylem and cambium may be visible), epidermal cells, and sclerenchyma bundles (Pearlstein, lecture 28 January 2014). Samples were prepared by cutting a very thin slice from the end of a monocot stem using a scalpel and carefully placing the sample on a glass microscope slide, followed by a drop of water and a cover slip.

Image: Lesley Day

Image: Lesley Day


Image: Lesley Day

Image: Lesley Day


Image: William Shelley

Image: William Shelley


Image: Betsy Burr

Image: Betsy Burr

In addition to taking really beautiful and informative photomicrographs, students gained valuable experience with sampling techniques.  The challenges of isolating single fiber ultimates or obtaining good cross sections on the reference materials, illustrated that much experience and care are necessary when taking samples from actual artifacts.  Once students were able to see the differences between features, locating them without sampling was possible in some cases!   

References Florian, Mary-Lou E., Dale Paul Kronkright, and Ruth E. Norton. The Conservation of Artifacts Made from Plant Materials. Getty Publications, 1991. Pearlstein, Ellen (2014). Other Plant Materials, Lecture in Structure, Properties and Deterioration of Organic Materials, UCLA, Los Angeles, CA, January 28th , 2014.  

by Lesley Day (’16)


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Tight, Aligned Joins Does Not a Sprung Vessel Make

In our first quarter class, CAEM 260: Structure, Properties, and Deterioration of Ceramic, Glass and Glazes, we were assigned a ceramic object on loan from  Southwest Museum of the American Indian Collection, Autry National Center to examine, document, and treat the following quarter. I was given a low-fired, light-colored Chiriqui vessel whose largest condition issue was its fragmentary state; the vessel was in 5 large fragments with additional small pieces in an accompanying bag (Fig. 1). As I would soon learn, assembling a broken vessel is not simply putting a puzzle back together and finding which pieces go where. The stress released as a vessel is broken can result in fragments that don’t quite meet up to complete the object as it was before—and I learned exactly how frustrating it can be to achieve tight and aligned joins with stubborn objects like this!

Fig. 1. A soon-to-be joined Chiriqui vessel, comprised of 5 large fragments and several small pieces.

Fig. 1. A soon-to-be joined Chiriqui vessel, comprised of 5 large fragments and several small pieces. Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 491.G.1524

 

Joining my vessel (with 40% Acryloid B-72 in acetone using a brush) went quite well in the beginning, such as with Fragments C and E  (Fig. 2).

Fig. 2. Fragments C and E prior to joining (a) and after joining (b); the resulting join was tight and aligned (c).

Fig. 2. Fragments C and E prior to joining (a) and after joining (b); the resulting join was tight and aligned (c). Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 491.G.1524

 

I determined the best sequence would be to join Fragments C-E-A and Fragments B-D (Fig. 3).

Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 491.G.1524

Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 491.G.1524

 

These two sections would then come together to complete the vessel…however this didn’t prove to be as easy as I had thought. I found that while one side of the join was well aligned and tight, the other side by comparison was like a mile-wide fissure as far as I was concerned (Fig. 4); a jolting discovery for a newbie in training! The two sections just didn’t fit, despite careful and tight joining of the fragments that comprised them.

Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 491.G.1524

Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 491.G.1524

 

Any ideas I had about merely adding adhesive and piecing the vessel back together were naively simple and optimistic in hindsight, but fortunately lab manager and conservator, Vanessa Muros, was able to guide me through a more complicated (and at times scary!), multi-stage aligning method involving heat and pressure. The misaligned fragments were adjusted using a hair drier (set to a low temperature) to soften the B-72, and then pressure was applied using 3M Coban self-adherent wrap and soft-grip clamps, with barriers of thin Ethafoam and Volara (Figs. 5-6); slow tightening of the Coban wrap was performed regularly using a wooden popsicle stick. This process may seem simple, but pressure was required in multiple directions and aligning one area often caused another to move and misalign; all joins had to be considered. It became a battle over control between what I wanted the fragments to do and how they naturally wanted to be, all while gauging the safety of the object and determining when enough was enough.

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Figures 5-6.  Alignment of the joins. Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 491.G.1524

Figures 5-6. Alignment of the joins. Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 491.G.1524

 

In the end, relatively good joins were achieved overall (Figs.7-8). The changes that occurred from the stress released upon breaking still prevented perfectly tight and aligned joins everywhere, but the best compromise was achieved and the results were more than satisfactory. I was able to learn about the unforeseeable problems that can occur during the treatment of ceramics, and I gained a greater feel for the material and how it behaves…and I’ll be ready for the next one!

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Figures 7-8.  Vessel after treatment. Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 491.G.1524

Figures 7-8. Vessel after treatment. Southwest Museum of the American Indian Collection, Autry National Center, Los Angeles; 491.G.1524

by Heather White (’16)

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