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archaeological conservation

Ugly Object of the Month — March 2021

By Suzanne Davis

Color me happy, folks, because this scrappy little bit of tattered textile is exciting to me. Excavators working at Karanis, Egypt, back in the 1920s saved hundreds of little textile fragments like this one, and when you open the cabinets here at the Kelsey where these are now stored, it’s kind of overwhelming: tray after tray after so many, many trays of small, janky bits of dirty fabric. Bits that, if I found them in my garage, I’d probably burn. The Karanis excavators, thankfully, were smarter than I am,* because with careful attention these little bits have a lot of information to offer. Information about fibers and yarns, weave structures, and decorative techniques. 

ancient textile
Fragment of a wool textile. Roughly 8 x 10 cm, Karanis, Egypt. 2nd–4th c. CE. KM 10426.

And now I’m excited because our recent grant from the NEH is going to take our knowledge of them to a new level—for the first time, we’ll be studying the dyes that were used on these. I’ve been so excited by this that when I open the storage cabinets, I can’t choose! There are so many cool colors—reds, blues, greens, purples—and these are represented on so many interesting fabric constructions, from plain weave to patterned to sprang (trust me, you’ll be seeing sprang here before this all over). This particular scrap is interesting to me because it has a deep blue-green wool for the stripe. I know it looks almost black in this photo, but in real life, it’s an intense blue-green stripe on a faded orange background. Stay tuned: I hope to report back sometime in the fall with more information about at least some of these Karanis colors. 

 

* To be fair, if the Karanis excavators had been working in my garage, they might have burned these, too, so perhaps I should give myself more credit. 

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News from the Conservation Lab — NEH Research and Development Grant

By Caroline Roberts, Conservator

Suzanne and I are thrilled to report that we’ve received an NEH Research and Development Grant to study ancient color in the Kelsey collection. This project will allow us to conduct multispectral imaging and XRF analysis on a large group of painted and dyed artifacts from Roman Egypt, including objects from the University’s excavations at Karanis and Terenouthis. As we conduct the study, we will develop a scalable research protocol that can be adapted for use in other archaeological collections.

For many years, ancient color research has focused on artifacts from elite contexts. The data gathered from our study will inform us about the colors used by artists working for everyday people living in the Roman Empire. An important, broader goal of the grant will be to make this type of research more accessible to small research institutions like ours, both at the University of Michigan and elsewhere. We look forward to keeping you updated as we roll out this project over the next two years!

Left: Carrie performs multispectral imaging (MSI) on a mummy portrait from the Fayum region of Egypt. Right: A closeup of the portrait, KM 26801.

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Ugly Object of the Month — November 2020

By Suzanne Davis, Curator of Conservation

Greetings, Ugly Object fans. How are things going for you? If you’ve been feeling exhausted and strung out, you’re not alone. Luckily, the Kelsey Museum of Archaeology is here to take you on a restorative mini-break to the ancient world. This month’s Ugly Object — an offering tray in the shape of a brazier — looks plain and unassuming at first glance, but it’s interesting for several reasons.

Ceramic tray in the form of a brazier (foculus). Etruscan, 550–500 BCE. KM 3087.

First, it was probably once part of a funerary set that included miniature banquet vessels and serving utensils. For two much fancier examples, see this set at the Penn Museum and the object below, part of the collection at the Metropolitan Museum of Art in New York. As the Met’s catalog entry indicates, these sets may imitate actual banquet ware in use during the Etruscan period.

The Met’s awesome funerary set: Terracotta focolare (offering tray). Etruscan, ca. 550–500 B.C. MMA 96.9.145a.

If you are into ceramics technology, the trays above are also good examples of bucchero, the signature pottery of Etruria. The dark gray surfaces of these pots are produced with a reduction firing technique in which the kiln’s oxygen levels are decreased and carbon monoxide is increased, for example by closing the kiln vents and adding green or undried wood. This causes a chemical reaction that converts the iron oxide minerals in the clay from red-orange to gray-black in color.

The Kelsey’s tray is also interesting from a historic conservation perspective. When I first saw it, the surface was completely covered with cellulose nitrate, a synthetic resin that archaeologists and conservators once thought would provide a preservative coating for artifacts. It was used widely until the late 1970s when conservators began to notice it was shrinking, peeling, turning yellow, and generally making a mess of original, ancient surfaces. At the Kelsey, we see cellulose nitrate coatings on most of our excavated materials including ceramics, metal, bone, and wood. It is a great argument for the tenet of minimal intervention (less is more!) in modern conservation philosophy.

This object has been on my mind lately because it’s essentially a miniature banquet tray in the shape of a mini ancient fire pit. And I recently had the lovely experience of relaxing around a full-size fire pit with three of my Kelsey coworkers. Although we did not feast on a banquet, we did try a classic Michigan cocktail, the Hummer, which I saw in a recent book from our colleagues at Michigan Radio and the University of Michigan Press. You can pick this little gem up from U-M Press or from Literati or Nicola’s bookstores here in Ann Arbor. When archaeology mini-breaks are no longer enough, a crackling fire, comforting beverage, and cheerful conversation might be just the ticket to help you make it through the winter.

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August News from the Conservation Lab — Conservators in the house!

By Caroline Roberts & Suzanne Davis

We are back in the lab!!!

Suzanne and I are very excited to be back at the Kelsey doing conservation and collection-focused research a few days a week. Here we are preparing some of the Kelsey’s Terenouthis stelae for photography.

selfie of two women wearing masks
Socially distanced selfie with stelae from Terenouthis, Egypt, 3rd–4th centuries CE.

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News from the Conservation Lab — Kelsey Dig Wanderlust

By Suzanne Davis, Curator of Conservation, and Carrie Roberts, Conservator

The inability to travel to the Kelsey’s field sites due to the COVID-19 pandemic has made us, well, crazy to travel to the Kelsey’s field sites. If you, too, are experiencing serious wanderlust, we invite you to take a quick photographic mini-break with us. Here’s a beautiful photo and something we love about each of the four sites we currently support.

 

Suzanne loves the incredibly good-looking site of Notion, Turkey. It’s got everything a conservator could want — the romantic ruins of an entire ancient city, lots of conservation work to be done, and a beautiful seaside location.

View over a ridge with shrubs onto the ocean below
Notion, Turkey. View of the site from the west at sunset; the ancient city is located on top of the yellow, sunlit hill. If you look closely, you can see the Fortifications.

 

This spectacular photo of the ancient temple, cemetery, and city site of Jebel Barkal, Sudan, makes Suzanne miss the desert sunshine and all her fellow Jebel Barkal and El-Kurru teammates.

aerial view of small pyramids in the desert
Jebel Barkal, Sudan. This image shows the remains of some of the site’s pyramids, with Jebel Barkal (in Arabic – the holy, or pure, mountain) in the background. Photo by Kate Rose.

 

Carrie is inspired by the ancient landscape of Abydos. It’s great to drink a cup of coffee with the team at sunrise and know that the Seti I temple is only a 10-minute walk from the dig house, while the early dynastic tombs below the desert cliffs can be reached in 20 minutes.

photo of a house in the desert
View of the front courtyard of the Abydos dig house at sunrise.

 

At El-Kurru, Carrie loves village life — walking from the house where we live to the temple site and saying hello and how are you to neighbors on the way, then grabbing a snack at the corner store at the end of the day. She also misses the family we live with, especially the kids.

men in front of a low beige building in Sudan
El-Kurru, Sudan. On the left is Kurru’s hardware store, and on the right is the barbershop.

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News from the Conservation Lab — June 2020

By Caroline Roberts, Conservator

These past few weeks have been horrific, and have made me question things I’d previously taken for granted. Among them is the idea that a person in my profession should remain neutral, objective, and scientific in their approach to preserving cultural heritage. As I see other conservators grapple with ethically problematic projects — like the removal of graffiti left by peaceful protesters — I’m beginning to understand the limits of this approach. None of us can fully separate our work from our values. We conservators can and should be active participants in determining how to make our country’s often painful cultural heritage accessible for the future while supporting the need for people to speak out, reject hate, and heal. And now more than ever we need to ensure that a greater number of Black, Indigenous, and people of color are part of this decision-making.

The American Institute of Conservation’s Equity and Inclusion Committee has presented the field with guidelines for how to increase diversity in our profession. The ECPN-HBCU mentorship program, along with similar programs run through the conservation graduate schools, is matching students from underrepresented groups with mentors in an effort to actively recruit at the undergraduate level. And Sanchita Balachandran’s Untold Stories initiative seeks to make the conservation profession more representative of the heritage we preserve. There is still a lot of work to do, and we need to acknowledge the barriers that remain in place for people of color pursuing careers in conservation. We have a responsibility to sustain these efforts, for the good of our profession and for the future.  

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small marble hand and arm

News from the Conservation Lab — Pretty in Pink

By Caroline Roberts, Conservator

I’ve been spending a lot of quality time in collections storage lately and have noticed something curious: an abundance of pink! Namely, ancient pink pigment. Why is this so interesting? Because the pink most frequently used in the ancient Mediterranean was made of madder root, a plant-based dye that was used to color textiles as well as a pigment on objects.

Like other organic pigments, rose madder is highly light sensitive and prone to fading. The occurrence of rose madder on so many artifacts in the collection surprises me, given what we know about its fugitive nature. Rose madder also has a unique chemical property that causes it to luminesce, or glow, an orange-pink color when exposed to ultraviolet light. A quick look with a UV LED flashlight can help confirm whether or not the pink on an object is madder.

small terracotta hand and arm

Marble sculpture fragment KM 1931.441 from Seleucia with pink pigment between fingers and inside elbow.

sculpture fragment under two different kinds of light
Visible and ultraviolet-induced luminescence (UVL) images of KM 1931.441 showing orange-pink luminescence of rose madder.

Despite its tendency to fade, I am finding pink on everything from terracotta figurines to marble sculpture to limestone grave markers. I’m also finding it in different hues and on different decorative elements, from flesh tones to jewelry to architecture.  It turns out pink is everywhere at the Kelsey, and it is pretty fascinating.

small headless terracotta statuette with pink painted necklace
Marble sculpture fragment KM 1931.15 from Seleucia with pink-colored necklace.

stone with pink pigment
Remnants of pink paint on the surface of KM 21107, a limestone funerary stela from Terenouthis.

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A large machine

December News from the Conservation Lab — X-Rays and Electron Beams!

By Caroline Roberts, Conservator

As an archaeological conservator I know that, sometimes, you need to travel to where the work is. This was on my mind last month when I found myself flying back and forth across central campus, between our lab at the Kelsey Museum and the Electron Microbeam Analysis Laboratory (or EMAL). EMAL is a shared access research space within the Earth and Environmental Science Department, and it’s home to a range of instruments used for materials analysis.

I had a clear mission: to identify the composition of modern architectural limes and mortars from Sudan. Suzanne acquired the samples during the 2019 El-Kurru field season, with the goal of determining whether they were safe for use in architectural conservation at the two Sudanese archaeological sites where a Kelsey team is working.

I used x-ray diffraction and scanning electron microscopy to identify the unknown materials, processes that involve careful sample preparation, instrument setup, and data interpretation. It was time well spent since we now know that some of these materials contain gypsum, which poses risks to archaeological stone. This kind of information is crucial for informed conservation decision-making in the field, and will help shape architectural treatment and preservation plans for the El-Kurru and Gebel Barkal heritage sites.

A large machine
Samples loaded into the Rigaku x-ray diffractometer.

Woman standing next to and looking into a large machine
Not-so-patiently awaiting XRD results!

December News from the Conservation Lab — X-Rays and Electron Beams! Read More »

woman with clipboard

News from the Conservation Lab — Stone Survey!

By Caroline Roberts, Conservator

This summer I’m embarking on a condition survey of the Kelsey’s stone collection, a big project both in scope and in terms of artifact size. As I mentioned in our latest Ugly Object post (ancient earplugs!) the Kelsey’s stone collection is wide-ranging, including everything from tiny steatite scarabs to massive column drums the size of tree trunks. My survey will focus on the larger-scale artifacts and will include vessels, sculpture, and architectural elements made of stone. My goals are to identify which of these artifacts are most in need of conservation intervention, and in the process learn what I can about past stone conservation treatments.

woman with clipboard
Carrie examines stone artifacts in the Kelsey’s collections storage.

The project is a continuation of previous condition surveys conducted by Suzanne Davis, Claudia Chemello, and LeeAnn Barnes Gordon. Their work serves as a valuable baseline for how the Kelsey’s stone artifacts might have changed over the past ten years. Gordon’s research also revealed information about how newly excavated stone was treated at the Roman-Egyptian site of Terenouthis. In the early twentieth century, archaeological chemist Alfred Lucas introduced polymeric materials to archaeologists’ conservation toolkit. Among these was Duco cement, a cellulose nitrate adhesive that was applied to many of the stelae discovered at Terenouthis in order to prevent rapid surface deterioration following excavation. The Duco coating has, however, started to deteriorate, compromising the very surfaces it was meant to protect. Information about historic conservation treatments, along with new condition rankings, will help me develop preservation and treatment plans for the most at-risk stone artifacts at the Kelsey.

stone stela in situ.
Limestone stela during excavation at Terenouthis, Egypt. Kelsey Museum Photo Caption Database.

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photo of daffodils

News from the Conservation Lab — Conservation Conference Season

By Caroline Roberts, Conservator

Spring has officially sprung here in Ann Arbor, which means that the sun is (sort of) shining, the townies are out and about, and the next American Institute for Conservation (AIC) annual meeting is just around the corner. Suzanne continues in her role as VP/ organizer-in-chief of the conference program, whose theme this year is “New Tools, Techniques and Tactics” in conservation. This year I’ve got a pretty cool job too, as I’ll be chairing a special session on research strategies in settings with limited resources (think archaeological sites, small museums, etc.). This is a topic I’ve been interested in for a while, and I was happy when it was accepted as one of six concurrent sessions that are proposed and organized each year by AIC members.

The idea of member-proposed sessions is relatively new to AIC, and a great thing about them is that they tend to cover topics that appeal to conservators who work on different materials (like objects, paintings, books and paper, textiles, etc.). Other session topics include imaging, gel cleaning, and contemporary art conservation. Conservators and scientists presenting in my session work within a range of specialties, including architecture, archaeological materials, indigenous heritage, electronic media, and preventive conservation. I’m interested in learning how these folks figured out how to conduct analysis on materials in remote areas, or adapted a well-known investigative technique to a new research question. In other words, I want to explore the penchant for problem-solving that so many conservators have, regardless of the types of objects they work on.

For any conservators reading this post, we encourage you to drop in on one of these sessions and hope to see you at AIC New England in May!

photo of daffodils
Evidence of spring outside the Kelsey!

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