The class started with the week’s readings – L. Spaabaek’s “Conservation of Mummy portraits at the Ny Carlsberg Glyptotek” and M. Cannata’s “Funerary Artists. The Textual Evidence.” Learning of the panel conservation efforts of the 19th century archeologists, we were at first appalled by W. Flinders Petrie’s conservation strategy: heating up the existing wax on the portraits in the attempt to return the paintings to their original luster, or adding new paraffin wax on top of them. We discussed how conservation and technical analyses have changed over time – in the 19th century, researchers took large samples out of the artifacts to test out materials’ composition and properties, but now, this can be done without damaging the object using several new methods, including ones we are studying. From Cannata’s “Funerary Artists”, we learned that the artists of Roman Egypt were from lower economic classes, and that they joined professional guilds to reach more clients, to be exempted from material tax and to raise their social status. We also understood that the materials required for painting—including pigments, for example—could have been provided by the client, or the artist could have been reimbursed for the cost of acquiring what they required. Cannata also points out that while painting of mummy portraits was more likely completed by people with Hellenized or Greek names, the work of actually preparing the mummy was completed by priests with more Egyptian names, and was possibly carried out by indigenous Egyptians.
Before starting our work, we looked at some of the raw materials used in mummy portraits. We saw two bags of natural beeswax– bleached and unbleached. This is the basic material used in encaustic. The bleached wax had a light yellow color while the unbleached wax was golden yellow. The unbleached wax had a stronger and more natural smell. It is believed that Egyptians bleached their wax by boiling and putting it out in the sunlight. We also examined two bags of gum Arabic—also known as acacia gum—which is the exudate from acacia trees which were fast-growing trees present in ancient Egypt. The natural state resembled reddish-orange translucent crystals while the ground gum arabic was white colored and felt starch-like. This gum was used extensively in ancient Egypt and has been as one of the binders for paints and ground layers in mummy portraits. We also used it in our own recreations of portraits.
For the rest of the class, we went back to study our multispectral images from last week. We were still excited about the Ultraviolet Light Induced Visible Luminescence (UVL) images where the pigment madder lake glows a rose color. On the Portrait of a Man, we found madder lake on the nose, mouth, cheekbones, clavus (or stripe in the tunic), and neck. We also looked to see if the Infrared Reflected Image (IRR) showed us any trace of an underdrawing visible beneath the paint layers, and we think that the Portrait of Man might have one on his left eyebrow that measured out it’s thickness. However that is the only visible underdrawing. This made us question whether the artist very skilled in depicting individuals or was the face composition so similar to others he painted at the time that it was easy to render?
The most interesting observation with the Portrait of Man, however, was the presence of Egyptian blue. We were confused as to why we didn’t see this in the image from last week, but after re-shooting the Visible Infrared Luminescence (VIL) image, we saw that the entire background of the image glows, suggesting that the background is a white paint mixed with Egyptian blue! So even though the background looks gray in normal light, it might once have looked a little more like a light blue color. We also now noticed white spots of Egyptian blue on the man’s tunic in VIL; under the microscope, we found small spots of a dark blue pigment there even though the overall tunic looks bright white. We know from our readings that Egyptian blue was sometimes added to white to brighten it up—is this what is happening here? The Portrait of Young Man also has traces of Egyptian blue pigment as well – but not clearly visible in the background. However, it does seem to show up mixed in with the madder lake on the clavus of the tunic, making that stripe more purple than pink. Here, too, we see small blue particles mixed in with the madder lake under the microscope.
We can’t wait to find more!