objects conservation – The Kelsey Blog

objects conservation

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 — 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.

Ugly Object of the Month — August 2021

By Suzanne Davis, Curator of Conservation

Hello, Ugly Object fans! Although many Kelsey objects have seen better days—and we love them all dearly, because not every ancient object can be the prettiest, oldest, biggest, or best smelling—it’s hard not to have fleeting favorites. This month I’m really feeling it for a sad little scrap of cloth that looks like the tentacled remains of a decaying jellyfish and smells of ancient garbage dump.

Sprang fragment in visible light. Height 17 cm. Roman period, late 2nd–early 4th century C.E. Excavated at Karanis, Egypt, 1925. KM 13862.

You can’t deny that the colors are nice, though, right? And they should be, because our friend, scrotty little jellyfish rag, was once a stylish accessory for a well-dressed woman’s up-do; it is what’s left of a sprang “cap” from Karanis, Egypt. To see how the sprang weaving technique was used to create the Greek hairnet precursors to the sprang caps / ponytail and bun covers of Roman Egypt, check out this super fun video by professional hairdresser and amateur experimental archaeologist of ancient hairstyles Janet Stephens.

As previously discussed in this blog, the Roman Egyptian decorative world was highly colorful, and this little scrap of a cap is no exception. As part of a larger NEH-funded project to study color in the Kelsey Museum’s collections, I’m looking at dyes on textiles from Karanis, and this is one of the first objects I’ve spent time with.

Using a technique called multi-band imaging (also much discussed in this blog!), I’m able to tell that the dark blue dye used in this cap came from indigo, while the green dye is a blend of indigo and a yellow colorant, possibly weld. The bright red and the bright orange, meanwhile, are from a dye made of madder root. If you’re an archaeologist or conservator who wants to know more about how MBI (sometimes called MSI) can be used to study textiles, please see this excellent open-access article by conservation scientist Joanne Dyer and her colleagues at the British Museum.

Sprang fragment, infrared reflected false color image. In this image, an indigo-based dye is indicated by the bright red appearance of the yarns that are blue in the visible light photograph above, while the pink appearance of the green yarns indicates indigo plus a yellow colorant. The bright golden yellow of the red yarns, meanwhile, is characteristic of madder.

Sprang fragment, ultraviolet-induced visible luminescence image. Madder root dye is indicated by the bright pink luminescence of the yarns that are red under visible light.

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: https://fashionista.com/2017/11/justice-league-movie-costumes-2017)

News from the Conservation Lab — Artifact QT

By Caroline Roberts, Conservator

It’s October, and we are coming up on nine months of pandemic life. A lot of us are struggling right now, and trying to find comfort where we can. Being here at the Kelsey always gives me a lift. I just love spending quality time with the artifacts. Caring for them helps me put worries aside and grounds me in the here and now. Part of this comes from necessity — you really need to focus while photographing or treating an artifact — but there is also something meditative about working with an ancient object.

Egyptian faience ushabti figurine. Gift of Robert Gillman, 1952. KM 1980.4.35.

The ushabti figurine I’m treating today is one of thousands that were mass-produced in ancient Egypt. Its purpose was to serve the deceased in the afterlife; this particular one holds a sickle in each hand, ready to work the farm. Its turquoise color comes from copper minerals that were mixed with sand and salts and heated to form the figurine’s glazed surface. This ushabti is not only a tireless helper, it is also a really cool piece of ancient technology.

This artifact is in the lab because it needs a little TLC. And frankly, so do a lot of us. Let’s not forget to take care of ourselves — and each other — as we navigate these difficult times.

Ugly Object of the Month — September

By Caroline Roberts, Conservator

Hey, Ugly Object fans! It is great to be back at the Kelsey part-time and working with the collection again. One thing I’ve missed most about being away from the museum are the surprises — the chance discoveries than can happen while examining artifacts up close. This month’s Ugly Object is a rather unassuming funerary stela from Terenouthis, Egypt, showing a woman with upraised arms. At first glance, it doesn’t look like there’s much going on here beyond the carved figure, and I was not expecting to find more than a few small traces of pigment in the woman’s chiton. But as soon as I shined a UV light over the surface, hidden figures emerged! Look closely and you might be able to see a fringed shroud hanging over the woman’s left arm, an Anubis figure reclining on a plinth to her left, and below the woman’s feet … a painted inscription! 

Limestone funerary stela KM 21021 from Terenouthis, Egypt, late 2nd–early 4th century CE. Left, under visible light; right, under longwave ultraviolet light.

At what point did these images disappear? A photograph of the stela shows faint traces of the shroud, canine figure, and inscription, but the fact that they aren’t mentioned in the Terenouthis stelae’s published catalogue suggests that these elements had nearly disappeared by the early 1960s. Today, they are all but invisible to the human eye. Thankfully, some trace of the original paint remains in a form that is sensitive to UV light. This makes me wonder … how many other stelae have images and inscriptions that await rediscovery?

Stay tuned for more!

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.

Seated figurine carved from alabaster

Ugly Object of the Month — April 2020

By Caroline Roberts, Conservator

Greetings, Kelsey blog fans! I hope that you are all safe, healthy, and keeping it real at a sound social distance. We weren’t about to let today’s uncertainty get in the way of our ongoing celebration of Ugly Objects. So, it brings me great pleasure to present April’s pick: a seated female figurine from Seleucia. Seleucia on the Tigris was a Hellenistic capital city located south of present-day Baghdad and excavated by the University of Michigan from 1927 through 1937. Over 3,500 objects were recovered from Seleucia, including a myriad of figurines made of bone, ceramic, and stone.

Seated figurine carved from alabaster
Seated female figurine carved from alabaster, with bitumen repair resin at the neck and on the base. H. 12.8 cm. Seleucia on the Tigris, Iraq, 150 BCE–200 CE. KM 15879.

Our seated figurine is made of alabaster, a soft sedimentary stone with a uniquely translucent quality that made it a suitable material for window panes. Alabaster is easy to work, so we find a lot of vessels and figurines carved from it. But that same quality causes the stone to deteriorate easily. The alabaster block used to create this seated figure has broken along its bedding planes, causing the right arm to shear clean off the front of the statue. This type of inherent flaw might be what caused the head to detach — probably while the figurine was in use. Look closely and you can see traces of bitumen resin along the neck and on the base, signs of someone’s effort to repair the figurine in antiquity.

It amazes me how much we can learn from artifacts that were excavated nearly a century ago! Please keep reading our blog and visit the Kelsey website for opportunities to learn more about our collection.

multispectral imaging of an ancient stone stela.

News from the Conservation Lab — Work in Progress

By Caroline Roberts, Conservator

 Conservators wield some impressive photo-processing skills, in no small part because of the extensive photographic documentation we do in our work. We use our image-processing skills for research purposes, too.

Right now I’m taking multispectral photos of limestone funerary stelae from the Roman Egyptian city of Terenouthis so that I can begin to characterize the pigments that were used to paint them. Pigments reflect, absorb, and/or luminesce ultraviolet, visible, and infrared light in characteristic ways, but capturing a good image of these photo-chemical responses can be challenging.

Luckily we have access to the British Museum’s Technical Imaging web resource, a free downloadable toolkit that includes image setup, capture, and post-processing guidelines. The BM’s protocol has become an essential part of our own multispectral imaging setup, and an important research tool in my survey of color on the Kelsey’s stone collection.

multispectral imaging of an ancient stone stela.
Left: Limestone funerary stela KM 21107 from Terenouthis, Egypt, late 2nd–early 4th century CE, during multispectral image capture. Right: Infrared / visible image alignment in the British Museum technical imaging workspace.

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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