Conservation – The Kelsey Blog


News from the Conservation Lab – April 2023

By Caroline Roberts, Conservator

Hello, friends of the Kelsey Blog! The past six months have really flown by, haven’t they? Suzanne and I have spent quite a bit of this time traveling for work, something that we both missed during the pandemic. Here are some highlights!

In September and October, Suzanne and I returned to Abydos, Egypt, where we provide conservation for the Abydos Middle Cemetery (AMC) Project. We worked on a variety of things, including objects from the serdab of Weni the Elder, as well as newly excavated artifacts, alongside our Egyptian conservator colleagues Hamada Sadek and Ahmed Abdullah. Being back there—and being a part of the Weni project—was such a thrill. 

Single story white structure surrounded by sand and palm trees under a blue cloudless sky with rock formations in the background.
AMC dig house at Abydos, Egypt

In November, Suzanne and I gave papers at the American Society of Overseas Research’s annual meeting in Boston, where Suzanne presented her research on gender equity in museums and I participated in a workshop on Roman-Egyptian funerary portraits. It was great to see colleagues in the flesh once again after many years of virtual meetings and to be able to visit some old stomping grounds, including the Museum of Fine Arts, Boston, where I took in the newly reinstalled Greek and Roman galleries. Check out this truly inspired loom weight display (I love it so much I just had to share it with you folks)! We also enjoyed a tour of the Harvard Art Museums with recent IPCAA graduate Caitlin Clerkin, who works there as a postdoctoral fellow.

Five ceramic loom weights of various sizes and shapes attached to threads in a museum display case.
Ceramic loom weights, Museum of Fine Arts, Boston; Acc. #s 84.381, 84.373, 84.374, 84.370; Greek East, 6th–4th centuries BCE, from Assos (Behramkale, Turkey)

In January, Suzanne traveled to Jebel Barkal, Sudan, where she is directing site preservation with her team of conservators and conservation architects including Elmontaser Dafalla, David Flory, and Sefian Mutwakil. Check out her blog post and more news from Barkal here.

As always, there is a lot going on in the Conservation Lab! Keep tuning in.

News from the Conservation Lab — new lab gear to scope out old pigments

By Caroline Roberts, Conservator

The Kelsey Conservation lab has been in operation since the 1970s—thanks to former director John Pedley, who launched the conservation department here at the Kelsey—and some of our equipment likewise dates back a few decades. Our old binocular microscope may very well go back that far and has served us well over the years, allowing us to clean coins, count threads, and identify any number of salt encrustations. But this summer, we decided that the time had finally come to replace it. In its place we now have a Leica S9i stereomicroscope, and I am admittedly geeking out over it. The new ‘scope has an extendable arm that will allow us to perch the instrument over large objects, as well as a built-in camera, so we can simultaneously examine objects and visualize what we’re looking at in real-time on our laptops.

A young woman with short dark hair sits at a desk and works on a computer. A microscope is on the desk beside her.
Carrie examining KM 23976 under the new stereomicroscope.

Last week I used our new microscope to capture the chunky orpiment particles that are embedded in this yellow(ish) paint layer on KM 23976. This painted wood panel from Karanis depicts what looks like an eagle, and around its neck is a gold collar. The artist chose to use orpiment, a brilliantly yellow arsenic sulfide pigment, to create the pendant. Although it has faded and darkened over the centuries, the pendant would have practically sparkled in antiquity. No wonder orpiment’s Latin name, auripigmentum, means “gold pigment.”

A brown field with small gold flecks embedded.
Detail of orpiment particles in the painted pendant on KM 23976.

Be sure to stay tuned for more cool images from our new ‘scope!

News from the Conservation Lab — Laurel Fricker!

By Caroline Roberts, Conservator

This month’s Conservation blog post serves as a send-off for Laurel Fricker, our wonderful graduate student researcher for the Color Project. Laurel is finishing her third year in the IPCAA program and will be spending her fourth year at the American School in Athens. We are so excited for her, and so sad to see her leave! We wanted to feature Laurel once more on the blog before she heads off on her Greek adventures and get her take on her experience exploring ancient polychromy at the Kelsey over the past year.

Laurel conducts MSI on a terracotta figurine.

Carrie: Hey, Laurel! I love that you are as excited about ancient color as we are, however, I know your research interests go beyond this topic. Can you tell folks more about them?

Laurel: I primarily study houses and households in ancient Greece and I am really interested in exploring questions related to the daily lives and identities of the inhabitants of ancient Greek houses. To do this, I hope to take an object-focused approach where I will connect objects uncovered in houses with their findspots to see how much can be said about the different activities that took place in houses and what can be determined about the people who did those activities.

C: Awesome. So what drew you to the Color Project? What were you hoping to learn?

L: I have always been interested in the idea of exploring color on ancient objects, but I was never afforded the opportunity to do so until the Color Project. I was completely blown away when I was first told that ancient sculpture was originally brightly painted, as many of the objects held in museum collections and presented in textbooks are not often discussed in terms of their original color. I played with the idea of researching ancient color for a term paper during my master’s degree, but unfortunately it was not encouraged, and I did not pursue the topic any further. When I saw the announcement that Kelsey Museum conservators Suzanne and Carrie had won this incredible NEH grant in December 2020, I knew I had to reach out and see if I could get involved. Thankfully they said yes!

I don’t really remember what I was hoping for when I first joined the project; I just know that I wanted to learn as much as possible, gain new skills, and develop deeper connections with the Kelsey Museum staff. I can confidently say that I accomplished all three!

Suzanne, Carrie, and I could not start our work in the lab right away because of COVID restrictions on campus, so the first few months involved a lot of intense reading and research. This was really eye-opening for me! Carrie and Suzanne knew so much already because they had already been doing some multispectral imaging (MSI) of objects in the Kelsey collections and because of Carrie’s work curating the Kelsey Museum’s 2019 exhibition Ancient Color. I, on the other hand, was completely underprepared when I first started; there is a good amount of scholarship discussing different avenues for researching color on ancient objects and what other scholars have discovered through this work and I had a lot of catching up to do! I had not touched chemistry since high school and suddenly all these articles on X-ray fluorescence (XRF) were discussing different elemental compositions of pigments and other articles on MSI were presenting data on different wavelengths of light and what this meant for showing traces of pigments. I was definitely out of my comfort zone at the start, but it has been a lot of fun to see my growth over this year and to have all the articles I read early on start to make sense as I do the work in the conservation lab myself. I have learned a great deal and I am looking forward to continuing this work when I come back from my year in Athens!

C: How many objects have you looked at for the project so far? Which one is your favorite and why?

L: One of the goals of the Color Project is to study about 200 Roman Egyptian objects housed in the Kelsey Museum that have documented excavation contexts from Karanis and Terenouthis in Egypt. My role in the project involved researching the ceramic objects included in the list, primarily figurines from Karanis.

Over the past academic year, I spent around 120 hours in the conservation lab under Carrie’s supervision. During that time, I imaged and analyzed over 35 objects. Studying each object was a multi-step process: capture a condition record photograph, complete an MSI workup, process the MSI photographs, enter the MSI data into the spreadsheet, investigate the pigments with XRF, process the XRF data and enter it into the spreadsheet, record all the data in the appropriate way according to our data-management protocols, and then upload the most important information to the Kelsey Museum database!

Picking just one favorite object is really tricky! So here are two:

KM 6449, painted terracotta Harpocrates figurine from Karanis, Egypt, 2nd-3rd century CE.

First is KM 6449, a Harpocrates figurine standing next to a stove piled with bread, holding a pot,  and leaning on an amphora. Excavated at Karanis in 1935, this figurine is really fun because of the amount of color that has been preserved that is visible to the eye—red and blue on the stove, pink on the amphora and the pot, yellow for the amphora base and in the curly hair, and black dots on the bread and as a ground line. This object was a treat to study because it was incredibly cool to see all this preserved color. However, everything was not exactly as it looked to the eye. In addition to the pink visible on the amphora and pot (a pigment created from mixing red ochre and white), there was a different pink in the crown! This pink was only shown through MSI as the area fluoresced orange under ultraviolet light, meaning it is a rose madder. Then the blue turned out to be Egyptian blue—the MSI infrared image showed the blue area clearly luminescing. I really enjoyed the process of studying KM 6449 and it was one of the first objects where I finally felt confident and that I knew what I was doing!

KM 6578, painted terracotta Eros and Swan figurine from the Fayum region, 1st-3rd century CE. Gift of Peter Ruthven, 1935.

Second is KM 6578, a figurine of Eros on a swan rising out of waves. When I first joined the project and Suzanne and Carrie were deciding on the list of objects to study, this object was my first request. Sadly, this figurine does not come from a Michigan excavation—it is a purchase—but it is one of my favorite pieces in the Kelsey collection. Eros on the swan is another figurine with a great deal of color preserved and visible to the eye: the swan is white and has a red beak and feet and there are two different shades of purple on the swan’s wings, the waves are blue, and Eros still has a good amount of his skin tone. The purples are interesting because they are likely mixes of red ochre, a white, and differing amounts of carbon black to get the two different shades—this shows that the artists were capable of creating different colors and mixing pigments to get new shades. Also, this figurine had a lot of Egyptian blue present, both in the waves and in parts of the white of the swan, likely included to add depth and shading to the torso of the swan.

I could keep going—there are so many incredible figurines that I have studied this year!

C: I love those two! They both have some of the best-preserved color on any of the terracottas in the Kelsey collection. Can you tell our readers—why do you think it’s important to study color on archaeological materials?

L: I think color is a really important area to study because for too long our interpretation of the ancient world has been one that seems white, monochrome, and dull. But that is not the case; just like today, the ancient world was full of color! The architectural decoration of public buildings, the walls and floors of houses, figurines, votive offerings, pottery, and garments were all decorated and full of color and this fact is still only slowly gaining the attention of scholars. There is still this idea in popular culture that the white marble statues seen in major museums and presented in books are a reflection of notions of perfection and beauty. These ideas are incorrect and can be extremely harmful. I won’t go into detail about this here, but this has been written about by scholars such as Sarah Bond; one of her articles can be found here.

There are many different avenues that can be explored using color, including trade and connections when it comes to the sourcing and creation of pigments, questions of identity and the decisions that go into choosing different colors, and the cultural values and ideologies exemplified by different colors and pigments. Further, as I am interested in the lived experiences of people in the ancient world, every piece of information that helps me better understand their daily lives—including how colorful their surroundings were—is exciting!

C: It’s true that we have so much more to explore on this topic. But looking ahead, are there any cool sculptural or architectural polychromy you’re looking forward to seeing in Athens next year?

L: Next year I will be in Athens as a member of the American School of Classical Studies and part of the program involves site and museum visits all over Greece. While I am sad to be away from the Color Project and figurines in the Kelsey, I am very excited to see if my better-trained eye can pick out more traces of color on different objects on display now that I have a better understanding of the different pigments in use in the ancient world. I am especially excited to see the Peplos Kore and the Kore from Chios again, both on display in the Acropolis Museum in Athens. The two korai have traces of color preserved in their hair and on their garments. These large Archaic Greek marble sculptures are quite different than the small Roman Egyptian terracotta figurines that have been my friends for this past year, but they are just as fascinating. And I am excited to be surprised by color and see traces of pigments when I don’t expect them!

C: Thanks, Laurel! We can’t wait to hear all about it.

News from the Conservation Lab—analyzing ancient portraits and panel paintings

By Caroline Roberts, Conservator

Every time I walk through the first-floor galleries I like to pay a visit to KM 26801—the remarkable portrait of a woman on display in the museum’s Egyptian galleries. This arresting painting is a type of funerary object that was popular in Roman Egypt: a painted wooden panel that would have originally been secured via linen wrappings over the face of a mummy. Portraits like this one can be found in collections worldwide. They are often separated from their mummy, with their original findspots unrecorded and now no longer known.

We are taking a closer look at the Kelsey’s collection of panel paintings as part of the conservation lab’s ongoing NEH Color Research project, with the goal of adding what we learn to our growing color dataset, as well as to the APPEAR mummy portrait database. Multispectral imaging has allowed us to reinterpret the imagery of one panel painting (featured in an earlier blog post), and it has allowed us to identify pigments on mummy portraits in the Kelsey collection. On one painting (KM 26574, pictured here), the sitter wears a purple clavus (a decorative strip of fabric worn on the shoulder) that is painted in a way remarkably similar to the purple robe of the woman in KM 26801. On another, Egyptian blue appears in unexpected places in the figure’s skin—something we see in portraits from other collections. We also found another blue pigment—indigo—in the hair of a mummy portrait fragment that was discovered in a house at Karanis.

Fragment of a mummy portrait. Roman Egypt (Minia?), 2nd century CE. gift of Peter Ruthven. KM 26574.

All of this provides us with more evidence about the materials and techniques artists were working with when they painted these wonderful panel paintings and portraits. Just another day in the Kelsey conservation lab!

News from the Conservation Lab — Exploring bronze corrosion under the microscope

Harrison Biggs at the microscope.

This month we’re excited to welcome Harrison Biggs as our Conservation guest-blogger! Harrison is interning in the Conservation lab as part of the Museum Studies Undergraduate Program.

By Harrison Biggs, Conservation Intern

This semester I’ve been given the opportunity to work with Carrie and Suzanne as an intern here in the Kelsey Conservation lab. As an intern, I’ve been doing a lot of multispectral imaging and XRF analysis for the ongoing NEH Color Research project, but the project I’ve been most excited about lately is the treatment of this little bronze statuette (KM 3090).

Bronze Isis and Eros figurine. Graeco-Roman Egypt. Purchased from David Askren, 1925. KM 3090.

Even though treatment in this case just means picking harmful materials off the object with a pin (it’s more fun than it sounds), this has been a great opportunity to learn about the ways that bronze objects age. Bronze corrosion is an incredibly complex process where even small environmental changes can lead to the generation of drastically different minerals and patterns, but there are a few minerals that appear more than others.

Cuprite (Cu2O), a red-orange-brown copper oxide, and Malachite (CuCO3-Cu(OH)2), a pale green copper carbonate, are fairly common corrosion products that often form protective patinas on ancient bronze objects. Azurite (2 CuCO3-Cu(OH)2) is a less stable copper carbonate that tends to manifest as small blue crystals on an object’s surface. Nantokite (CuCl) is a soft, waxy copper chloride that forms commonly under burial conditions. When it gets too moist, Nantokite transforms into powdery, light green Paratacamite (Cu2(OH)3Cl), commonly referred to as “bronze disease.” Paratacamite is the main target of the treatment because, if allowed to spread, it can reduce an object to powder.

Together with a pile of less common and similarly colored minerals, these form a beautiful little world that I have the privilege of staring at through a microscope for hours at a time. I hope you enjoy looking at it as much as I do!

The surface of the figurine under 10x magnification.

News from the Conservation Lab — November 2021

By Suzanne Davis

Hello, readers! As always it’s a busy time in the Kelsey Conservation lab, and we are feeling excited about our winter work. Since we often focus on cool objects in this blog, I thought I would give you a little peek into all the other stuff we do, and I’m going to illustrate this with a photo of my messy desk / lab bench.

color photo of a desk strewn with papers and an open laptop. A gavel rests on top of a short stack of books.

At left there are samples of (modern) building materials we’ve been testing for use at the Jebel Barkal and El-Kurru archaeological sites in Sudan. Next, half-buried under other things, is a copy of the budget my colleague Geoff Emberling and I are working on for those two archaeological projects—we hope to be in the field in Sudan this winter.

The pile on top of this is related to board meetings for the American Institute of Conservation (AIC), and the Foundation for Advancement in Conservation (FAIC). As AIC president, I’m responsible for running the AIC board meeting, so I’ve got the presidential gavel (passed down from president to president since the 1980s) and my copy of Robert’s Rules of Order, the Classic Manual for Parliamentary Procedure (ditto). Tucked underneath this are my notes from those meetings, including a quote from my FAIC board colleague and friend, Bob Mitchell, who runs a successful consulting firm that focuses on marketing and strategy. The quote is, “What got you here, won’t get you there.” Bob believes it’s important to have a spirit that embraces change and re-imagination right now. I like this idea!

Next up is a messy clipboard with a flow chart that I’m consulting for identification of ancient dyes, and this overlays all my notes about the multispectral imaging I’m doing. Finally, on my computer screen is a copy of the schedule for the annual meeting of the professional archaeological association ASOR. It’s happening in Chicago this week, I and many of my Kelsey colleagues are participating in the conference, and we are very excited to attend it in person this year!

News from the Conservation Lab — Color research update!

By Caroline Roberts, Conservator

Greetings, Conservation aficionados! We are in the midst of the data-gathering phase of our NEH Color Research project, and so far we’ve imaged and analyzed over 50 objects from the Roman Egyptian sites of Karanis and Terenouthis. In the process, we’ve gathered data that both strengthens (and in a few cases has led us to question) what we know about pigments and dyes from this period in Egypt’s history. We’ve also been fortunate to have IPCAA student Laurel Fricker here in the lab to help us with our research. Laurel has a special interest in terracotta figurines and is looking at the surface decoration on painted figures from Karanis.

As I mentioned in a recent Ugly post, a few of the objects we’re looking at have yielded some unexpected results. Among them is an unassuming wall painting fragment that’s got green and red spots. The green spots are a real mystery. They have a weird element (chromium!) in their XRF signatures. Could this be a trace element? How common is it? Could it tell us something about where this pigment came from? So many questions to consider. We’ve also found arsenic on two horse pull-toys from Karanis. Could this be from an orpiment (arsenic sulfide) pigment that’s worn away? Or perhaps from a historic pesticide treatment? We just don’t know yet. But that’s okay—I love a good mystery!

News from the Conservation Lab — It’s Fall, Y’all

By Suzanne Davis

Campus is hopping with students and faculty here in A2, and I have to say—it’s pretty fun. Our Wolverine community is doing great on vaccinations and masking, and the energy from having everyone back together is inspiring. Meanwhile, here in the conservation lab, lots of projects are either continuing or just getting started.

A new(ish) project I’m especially excited about is the Kelsey’s Jebel Barkal Archaeological Project, which is gearing up for a 2022 winter field season in Sudan after being grounded during 2021. We have several generous sponsors for this work, including the Bureau of Educational and Cultural Affairs at the U.S. Department of State, which will be funding conservation work at the site through a large Ambassador’s Fund for Cultural Preservation grant. If you’d like to learn more, please visit our brand new website, which I and several of my colleagues have been developing over the past month. I encourage you to sign up for the Jebel Barkal blog and stay tuned, since we’re working on adding other social media.

If you’re a regular reader of this blog, you’ll know that we luuuuv fall around here. Luckily for us, it’s the autumnal equinox and the weather has turned right on schedule—from 80 degrees and sunny to 60 degrees and raining like crazy. We’re putting on sweaters and re-reading Colin Nissan’s McSweeney’s essay on decorative gourds. I’m not going to link it, because the language is too fruity for a family-friendly blog, but if you already know and love it, now is officially the time to get reacquainted.

Image by Janelle Batkin-Hall.

News from the Conservation Lab—Conservation in the movies

By Caroline Roberts, Conservator

This month I thought I’d offer up some entertainment—and a bit of trivia for those conservation and film enthusiasts out there. Curiously enough, even though we’re a small field, cultural heritage conservation pops up fairly frequently in film. This seems to happen when a screenwriter is looking for something visually compelling for their protagonist to do in their off time, i.e., while they’re not capturing ghosts or saving the planet from evil superhumans. Less often, conservation may feature within a cultural preservation adventure plot (“It belongs in a MUSEUM!” … oh wait, wrong profession …).

I’ve seen only one film that stars a real-life conservator—George Stout in 2014’s Monuments Men—but the fictional characters are just as fun (if not more so) to watch. I’m still holding my breath for a conservator to appear in a futuristic space saga …

There are far more comprehensive lists out there, but here are some of my favorite films in which conservation plays a central role (be warned, some of these tomatoes are pretty rotten):

  • Ghostbusters II (1989), starring Sigourney Weaver as Dana Barrett, a professional cellist and paintings conservator (!) who must save her son from the evil magician Vigo.
  • The Relic (1997), in which a statuette of a mythical forest monster is uncrated and wreaks havoc on an unsuspecting museum staff—including the conservation department (filmed at Chicago’s Field Museum).
  • Head Over Heels (2001), starring Monica Potter as Amanda Pierce, who paints the face of FBI agent Bob (played by Freddie Prinze Jr.) into a missing area of a painting she’s restoring for a Russian smuggler.
  • Monuments Men (2014), starring George Clooney as one of conservation’s founding fathers, George Stout, who led a team of Allied officers charged with saving cultural heritage from destruction by the Nazis.
  • Wonder Woman 1984 (2020), in which Diana (Gal Gadot) works at the Smithsonian as a conservator (or curator? or both?) but must take some PTO (or however she negotiated this with her boss) to stop an evil guy named Max from destroying the planet while also letting go of her lost love, Trevor (Chris Pine), and dealing with a disgruntled coworker-turned-cheetah, Barbara (Kristen Wiig).


Diana (Wonder Woman) treating a statue in Wonder Woman 1984. Photo by Clay Enos. TM & © DC Comics (source:

News from the Conservation Lab — exploring the Kelsey collection with X-rays

By Caroline Roberts, Conservator

Suzanne and I are excited to announce a new addition to our lab: a handheld X-ray fluorescence (XRF) spectrometer. We were able to acquire this instrument with the help of the NEH-sponsored Research and Development grant we received this year. This nifty-looking handheld device—which, to me, resembles something out of an original Star Trek episode—is engineered to generate a powerful X-ray beam. The X-rays are directed onto an object, where they are absorbed by atoms that make up the pigment particles in an ancient paint layer. This initiates a phenomenon called the “photoelectric effect” which results in a release of photons from the atom. These photons have quantifiable energy levels that are unique to specific chemical elements, such as iron, copper, lead, mercury, or arsenic. The XRF device can detect these photons as they leave the object, and convert this information into a graph that we can read. All of this can be done without removing a paint sample from the artifact.

XRF machine being used in a lab
Bruker Tracer 5g handheld XRF spectrometer positioned on a tripod over KM 21114, a limestone funerary stela from Terenouthis, Egypt, late 2nd–early 4th century CE.

We’ll use the XRF unit, along with our lab’s multispectral imaging kit and polarized light microscope, to identify pigments that were used on artifacts at the Kelsey, providing us with materials-based evidence of what artists were using to decorate objects and structures in the ancient world. For the NEH grant, we’ll be focusing our investigative efforts on the collections we have from Karanis and Terenouthis. We’re especially interested in learning which pigments people were using to paint artifacts in Roman Egypt, since there isn’t as much data from this later period as there is from earlier parts of Egypt’s history.

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