color research – The Kelsey Blog

color research

Ugly Object of the Month — Special DOUBLE UGLY post!

Caroline Roberts, Conservator, and Leslie Schramer, Editor

Greetings, Ugly fans! How is it already September?? Time has no meaning anymore … but luckily, we have our Ugly Object blogroll to keep us centered. 

We have a special treat for you today. That’s right, it’s a DOUBLE UGLY since, whether you noticed or not in the mad days of the bygone summer, we sort of failed to post July’s Ugly Object. 

Though separated by time and distance, these two Uglies have a few things in common. A) They are arguably NOT so ugly, and B) they are not what they appear to be. Let’s meet them, shall we?

KM 1798, mummy portrait, modern (19th century?) forgery, acquired by David Askren in the Fayoum in 1920, gifted to the Kelsey Museum.

The first object is a painted portrait of a woman that was purchased by David Askren, a colleague of Francis Kelsey’s who worked as a physician at the United Presbyterian Hospital in Asyut, Egypt, in the early 20th century. The portrait (along with two similar portraits purchased by Askren at the same time), is now believed to be a modern forgery. 

Thanks to our new NEH–funded XRF spectrometer, we now know more about the paint materials that were used to create this portrait—and it seems to confirm what our curators have long suspected. We found the elements barium, iron, lead, nitrogen, sulfur, and zinc in the background and in the woman’s hair and robe, as well as cobalt in the blue beads of her necklace. These are consistent with barium sulfate, cobalt blue, and zinc white—pigments that were introduced in the 18th and 19th centuries. 

We can learn a lot from forgeries like this one. For one thing, it demonstrates how the demand for Egyptian antiquities in Europe and the US drove some ethically dubious practices, from the production of fakes to the commodification of real artifacts, in the early 20th century. It also provides comparative physical evidence—pigments we would expect to see in a forgery from this time period—that can help us better separate authentic ancient portraits from fakes. Empirical evidence is key, my friends.

And speaking of fakes, check out this little guy. Looks pretty nice, right? Like a beautiful, polished sample of giallo di Sienna, I bet you were thinking. 

KM 29574. Modern plaster plaque painted as giallo di Siena, L. 15.5, W. 11.8, D. 1.5 cm. Presented by Miss Wanere on January 10, 1896. No provenance, No accession date.


You’ve been pranked! It’s not giallo di Sienna at all. It’s not even stone!! It’s a piece of plaster that’s been painted to look like stone! Because, why not? Why cut and polish a piece of relatively common stone when you could sacrifice many hours and possibly your eyesight adding painstakingly realistic details of veining and color to a rectangle of plaster with no apparent function other than to look pretty?

Not that there’s anything wrong with that. I’m a big fan of art for art’s sake. I’m just saying.

This little curiosity was given to the Kelsey Museum in the late 19th century. According to its Kelsey Museum accession record, it once belonged to a “Miss Wanere,” who gave it to the Kelsey on January 10, 1896. We don’t know where she got it, or why she had it. But evidently, she thought it belonged in a museum of antiquities. 

We don’t know a lot about this particular piece, but if you’re interested in the biographies of chunks of stone in the Kelsey Museum, you happen to be in luck. The Kelsey has over 700 pieces of ancient stone (yes, I’m aware that virtually all stone is ancient. No lectures, please.) fragments from various quarries and archaeological sites around the Mediterranean. Most were gathered (picked up, purchased, found) by Francis Kelsey himself, who liked them for teaching demonstrations. Others were donated by friends and acquaintances who no doubt knew of Kelsey’s penchant for old rocks of a decorative or architectural nature. All 700+ of these stone fragments (and this one stone look-alike) have been carefully studied by Michigan-affiliated scholars J. Clayton Fant, Leah E. Long, and Lynley McAlpine, who have written a nice little book about them. The illustrated catalogue, which is currently in production here at the Kelsey, focuses on archaeological context and object biographies, following each piece from its creation to eventual deposition in the Kelsey Museum.

We look forward to the day when we can announce the publication of this catalogue. In the meantime, you can come to the Kelsey and see a sampling of these marble fragments in person. They are on the second floor, tucked away in the drawers beneath the Roman Construction case. 


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 — 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 — 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.

News from the Conservation Lab — Indigo Subtraction Imaging

By Caroline Roberts, Conservator

 Suzanne and I are busy preparing for the data-gathering phase of our NEH-funded Color Research project, which is scheduled to begin next month. We’ll be investigating color on 200 ancient objects from Karanis, Egypt, including about 40 textile fragments.

Among the tools we’ll use is multiband imaging (MBI, previously referred to as multispectral imaging). MBI is a photographic technique that can be used to characterize textile dyes, and we’ve added a new method to our MBI toolbox: multiband reflectance (MBR) image subtraction for indigo—a blue, plant-based dye used in Egypt during the Ptolemaic and Roman periods.

multiband image of textile revealing indigo dye
Left: Visible light image of KM 13821, a split-tapestry woven textile fragment from Karanis. Right: MBR subtraction image of the textile revealing indigo dye in areas of white.

Indigo dye molecules absorb a lot of light at 660 nanometers (the end of the visible light range) and reflect a lot of light at 735 nanometers (the start of the infrared light range). We can capture these contrasting behaviors by using lens filters that allow the camera to record these specific wavelengths. When we combine images captured at 660 and 735nm using the “difference” blend mode in Photoshop, areas that contain indigo (which absorb and reflect at those specific wavelengths) appear white. On textile KM 13821 you can see that the dark blue horizontal tapestry bands contain indigo dye. This technique will be useful for identifying indigo and for mapping where indigo is located on an object. The latter will be helpful in areas where dyes have been mixed to create a modulated color and in places where the original color has faded or discolored over time.

We look forward to sharing more colorful discoveries like these as this project unfolds. Stay tuned!

News from the Conservation Lab — March 2021

By Suzanne Davis

Hello! Happy end of winter! This week in the conservation lab we’re pretty excited about two things. First, we just had a research study be published in the journal Studies in Conservation. Written with our colleague Andy Poli, in U-M’s Department of Mechanical Engineering, the paper examines the behavior of conservation adhesives in hot climates and focuses on an adhesive that we tested extensively at the hot field site of El-Kurru, Sudan. The article is titled “Paraloid® B-72/B-48N 1:1 as an Adhesive for Use in Hot Climates: Literature Review, Laboratory Testing, and Observational Field Study.” It’s about glue, basically, and it involves molecular and physical chemistry, making it a topic that is both boring and complicated to understand. BUT we worked hard to make the writing clear, accessible, and active. The reviewers seemed to appreciate this, and we hope other archaeological conservators will find this study useful for their work.

broken pot in a basket
A large pottery jar at El-Kurru, Sudan, in 2016 after our usual conservation adhesive failed due to high heat. Failure like this is why we started researching adhesives for use in hot climates.

Second, this month we’re beginning work in earnest on our new, NEH–funded study of color in the Kelsey’s collections, and I’ve been selecting textiles to examine. We’re still early in this project, and I’m struggling with how to choose fragments for analysis: Pretty colors? Interesting fabric constructions? Good archaeological context?  So far I’ve got some of all the above, although the latter is complicated by how the excavators at Karanis, Egypt, understood and recorded stratigraphy in the 1920s. Still, it’s a lot of fun, and we look forward to new discoveries.

textile fragments
A selection of textiles—all from Karanis, Egypt—for the just-beginning technical study of color in the Kelsey’s collections.

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. 

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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