Mummy Mysteries: International Science Project Uncovers Ancient Egyptian Secrets at the CMA

By Natalya Swanson, Winterthur/University of Delaware Program in Art Conservation, Class of 2020

(Left ) Funerary Portrait of a Woman, c. 138–192. Egypt, Roman Empire, Antonine. Encaustic on linen, overall: 26 x 19 cm (10 3/16 x 7 7/16 in.). John L. Severance Fund 1971.136. (Right) Funerary Portrait of a Man, c. 138–192. Egypt, Roman Empire, Antonine, early 2nd century AD. Encaustic on linen, overall: 24.8 x 19 cm (9 3/4 x 7 7/16 in.). John L. Severance Fund 1971.135.

Ancient portrait paintings provide a connection to the past and a rare opportunity to come face to face with people of another era living in Egypt between the first and third centuries AD. Two CMA favorites are providing vital clues to an international study about the materials and methods used in the construction of these ancient portraits.

The works Funerary Portrait of a Woman and Funerary Portrait of a Man are being investigated for the APPEAR (Ancient Panel Paintings: Examination, Analysis, and Research) Project. The APPEAR Project, an international collaboration launched in 2013 by the J. Paul Getty Museum in Los Angeles, brings together the results of research into mummy portraits and related artifacts such as shrouds, shrines, and complete mummies from collecting institutions around the world. Compiling this information all in one place allows an unprecedented understanding of the range of materials and techniques used for these works of art, permitting scholars to compare, identify, and authenticate portraits.

Cartonnage Mummy Case , c. 50 BC — AD 50. Cartonnage, painted and gilded, with glass inlays, Overall: 20.5 x 57 cm (8 1/16 x 22 7/16 in.). Gift of the John Huntington Art and Polytechnic Trust 1914.715.

Mummy Portraits

Ancient Egyptian funerary portraits, commonly known as “Fayum portraits,” were produced in ancient Egypt during Roman rule in the first to third centuries AD. After Romans occupied Egypt, the process of mummification became less important and emphasis transitioned to the outer shrouds of the mummy. Painted portraits replaced traditional cartonnage (above), or metal masks, and were incorporated into the wrappings of mummified human remains. It is thought that these portraits were painted during the subject’s life and hung in his or her home. At the time of death, the portrait was taken down, cut from its frame, and trimmed to fit the deceased’s mummy, to which it was bound.

During excavation in the nineteenth century, the portraits were cut or removed from their mummies, as they were appealing cultural artifacts. There are approximately one thousand extant mummy portraits, most of which now exist as separate paintings on a thin piece of wood or fabric support. Studying these portraits helps us to understand more about the influence of Roman culture on Egyptian traditions; to determine whether there were changes in the types of paints or substrates used over the centuries of Roman rule; and to establish a baseline of expected materials to which newly discovered or not-yet-studied portraits can be compared.

High Tech Uncovers Ancient Secrets

The ongoing analysis and technical research on the CMA’s Funerary Portrait of a Woman and Funerary Portrait of a Man began in July 2018. Objects conservators at the Cleveland Museum of Art have been conducting historical, technical, and analytical investigations, including imaging with various wavelengths of light (figs. 1–3), x-radiography, and identification of pigments, binders, and fibers (fig. 4).

Fig. 1 (left). “Normal light” photographs are standard in any conservation project, as they document the condition of the object. The positioning of the lights can be adjusted to record surface characteristics like planarity (fig. 2) or surface gloss (fig. 3).

The study began by preparing a mock-up panel using paint media and pigments that might be present on the CMA portraits (fig. 4, 5). Creating the panel gave conservators the ability to prepare materials that were available to ancient artists, aiding in the interpretation of the construction of the portraits.

Fig. 4. Natalya Swanson, graduate intern, teaches Celine Wachsmuth, pre-program intern, how to take a thread count of the fabric substrate. Thread count, weave type, and twist direction are just a few of the technical details recorded when writing a condition report for an artwork.
Fig. 5. CMA pre-program intern Margalit Schindler prepares animal glue for making distemper paint for the mock-up panel. In addition to distemper, encaustic, saponified beeswax, gum Arabic, and egg tempera mediums were prepared with pigments available to ancient Egyptians and Romans. The materials chosen for the mock-up panel were used as comparison while characterizing materials with multispectral imaging (MSI).

Multispectral imaging (MSI) was carried out on the portraits (figs. 6, 7) and the mock-up panel. This imaging technique uses different wavelengths of light to help illuminate and identify different materials in the painting without the need for removing samples or touching the object. Because the panel was constructed with known binding media and pigments, it acted as a point of comparison for material characterization and identification (figs. 8–9).

Other imaging techniques that are leading to enhanced understanding of the portraits include x-radiography and reflectance transformation imaging (RTI); the latter shows a detailed representation of the topography of the painting’s surface (fig. 10). Surface testing with x-ray fluorescence (XRF) reveals the chemical elements present in each color, providing important information about the types of pigments that make up the paint.

Fig. 6 (left). Natalya Swanson, graduate intern, holds a color card up to the camera for color balancing. Fig. 7 (right). Margalit Schindler, pre-program intern, assists Joan Neubecker, conservation imaging specialist, in taking infrared reflectography (IRR) images. IRR is a technique used to look through paint layers.

Finally, conservators took microscopic fragments of paint from selected areas and analyzed them using gas chromatography-mass spectrometry (GC-MS) and polarized light microscopy (PLM). These techniques uncover information about the paint binding medium and help to identify fibers from the fabric support.

Mock-up panel photographed with normal light (fig. 8, left) and under conditions for visible induced infrared luminescence (fig. 9, right). This MSI technique is used for identifying certain pigments such as Egyptian blue, which luminesces brightly when the image is captured within the infrared range of the electromagnetic spectrum.
Fig. 10. Reflectance transformation imaging (RTI) provides information about an object’s topography and has been utilized to capture inscriptions, including names and ages of some figures. RTI requires 72 images to be taken with one carefully controlled light source. Once all the images are captured, they can be digitally manipulated to examine the object’s surface.

Thus far, the project has been highly collaborative and the understanding of these objects has been enhanced by the shared information and expertise of the Cleveland Museum of Art’s conservators with their international colleagues. The investigation of these portraits is ongoing and the results will be added to the Getty APPEAR database to be compared with other portraits in collections worldwide.

Fig. 11. Visible-induced infrared luminescence (VIL) requires the portraits to be illuminated with full-spectrum LED lights that have the infrared (IR) portion of the spectrum blocked out. The portraits are exposed to over two dozen flashes of light across the presentation surface of the painting.
Natalya Swanson, graduate intern, taking 100-microgram (1/1000 gram) samples using a tungsten needle under a stereomicroscope. The samples were sent to J. Paul Getty Museum conservation scientists who will carry out gas chromatography-mass spectrometry (GC-MS) — an analytical tool used for characterizing paint binding media.

Special thanks to the following CMA conservation staff for their contributions:

Beth Edelstein, objects conservator; Joan Neubecker, conservation imaging specialist; and Dean Yoder, conservator of paintings