ancient color – The Kelsey Blog

ancient color

Ugly Object of the Month – November 2022

By Caroline Roberts, Conservator

Greetings Earthlings! We have another feature from our NEH-sponsored Color research project this month—another Isis Aphrodite! This time she has taken the form of a small-but-mighty polychrome figurine from Karanis. Our graduate assistant Laurel Fricker did some sleuthing and discovered that this may be an Isis Aphrodite Anasyromene, or Aphrodite lifting up her skirt. Hers isn’t exactly a skirt—more like a robe—and it is painted purple. Purple paint is a source of intrigue to scientists. You could produce it in a lot of different ways, by combining a variety of red, pink, blue, and black pigments. Sorting these mixtures out can present a challenge when investigating purple on artifacts. The purple on this Aphrodite is one of only two instances of this color we’ve found on a painted object from Karanis. It’s a mixture of rose madder and another unidentified pigment—we’re still working on figuring this out.

Having studied over 100 objects from Karanis and Terenouthis, it’s interesting that we’ve found such a small number of purple-painted pieces (only three total!). Not sure what this means yet, but stay tuned!

Painted terracotta figurine of Isis Aphrodite under visible light on a light gray background.
KM 6488, painted terracotta figurine of Isis Aphrodite; Roman Egyptian,
1st – 3rd century CE; discovered at Karanis in 1928
Painted terracotta figurine of Isis Aphrodite under ultraviolet-induced visible luminescence (UVL). Thin lines of fluorescent colors on the crown and robe show areas of madder pigment.
Ultraviolet-induced visible luminescence (UVL) image of the figurine showing orange-pink fluorescent madder pigment in the crown and robe.

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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.

WRONG!

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. 

 

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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!

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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!

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Ugly Object of the Month — November 2021

By Caroline Roberts, Conservator

This month’s Ugly Object—a fragmented wood panel painting from Karanis—is a visual challenge. One interpretation I’ve read describes what we’re seeing as hair. But to me, this looks like a figure. Take a look at the infrared (IRR) image I captured—what do you see? I see some kind of furry (or feathery) creature with a pendant hanging around its neck. I think I see a bit of a wing and two bird legs. And I think I see a wreath-like object in front of those feet. Could this perhaps be an eagle with some imperial imagery thrown in? This is my best guess, and I’m sure there are other possibilities. What do you think, readers?

KM 23976, panel painting of a bird (eagle?). Roman Egypt (Karanis), 1st–5th centuries CE. Left: visible light image; right: infrared (IRR) image.

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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!

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Ugly Object of the Month | September 2021

By Caroline Roberts and Suzanne Davis

Fragment of a wall painting from Karanis, Egypt, first–fifth centuries CE. KM 26982.

This small and funky fragment of wall painting—excavated at Karanis in 1924—is part of our lab’s technical color research project. What exactly does it show, you might ask? Good question. We knew we were looking at fleshy bits of a human, but we spun this sucker around and around trying to guess what bits. Suzanne thought it was an arm (with an elbow joint) and an archaeologist friend thought it was a leg. Annoyingly, the ancient painter did not define the anatomy well enough for us to make a clear determination based on the joint in question. In the end, however, we decided our archaeology buddy (shout-out to Craig Harvey!) was right, based on … wait for it … the garment we see on display here.

What is obviously a highly fashionable couture cloak is draped luxuriously behind the figure, and the way this falls makes more sense for a leg than an arm. This lovely pale pink garment is lined in blue-gray, with black detailing along the seam of the lining. Seen against the pink of the outer fabric, the lining looks almost purple. And here is where the color research comes in.

The pink is rose madder, but what is the blue-gray-almost purple color? When we imaged (MSI) and analyzed (XRF) it, we discovered that it doesn’t contain Egyptian blue. This isn’t totally surprising, since the color doesn’t much resemble Egyptian blue (which tends to be more greenish), but how did the painter get this shade? The color contains iron and titanium, and it turns out that the black lines in this fragment are also from a paint rich in titanium and iron. So the black pigment isn’t a typical carbon-based black, but—whatever it is (and we have a good guess about this, actually)—it’s probably being used to create the purplish/bluish cloak lining.

Bottom line, this pigment could be what’s known as “optical blue,” a mixture of calcite and black pigment. Alternatively, the fragment could be from a later but still extremely cool period where people were wearing awesome cloaks. Excavation records link the fragment to a wall in a room in a house dating to the first–fifth centuries CE, however, so we’re still believing it’s ancient. But we will need to bring in other forms of analysis (possibly FTIR) to pin down exactly what pigment we’re seeing here.

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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.

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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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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.

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