Progress update on the stola coffin treatment

For the past few weeks, it has been full steam ahead on the treatment of the stola coffin lid. The lid is made of smaller pieces of wood joined together, then covered generously in areas with a thick layer of coarse mud plaster, followed by a thin layer of a finer mud plaster, followed by paint and a varnish. There are also raised details that were built up with gesso before painting.

This large piece of painted mud plaster (detached from the foot of the coffin, seeing on the left) is 11 cm thick.

This large piece of painted mud plaster (detached from the foot of the coffin, seen on the left) is 11 cm thick.

This area of damage clearly shows the wood substrate (green arrow), coarse mud plaster (blue arrow), and finer mud plaster (red arrow).

This area of damage clearly shows the wood substrate (green arrow), coarse mud plaster (blue arrow), and finer mud plaster (red arrow).

The two major condition problems on the coffin are found in the mud plaster layers: the coarse mud plaster has lost cohesion and in many places has separated from the wood below, and the finer mud plaster has also lost cohesion, so much so that it has deteriorated to a fine powder in places. I have spent over 150 hours so far readhering detached plaster, consolidating the powdery plaster, and realigning and stabilizing loose fragments on the coffin. Today I’m posting a few before and after treatment details to show the progress.

Here are before and after details of the top of the head showing an area where I had to readhere some large fragments of painted plaster:

Top of the head before (left), during (center), and after (right) reattaching painted plaster fragments

Top of the head before (left), during (center), and after (right) reattaching painted plaster fragments

Here are before and after details of the left eye showing the consolidation of exposed powdery mud plaster:

Detail of losses near the left eye before, showing powdery mud plaster (left) and after cleaning and consolidation of the mud plaster in the losses

Detail of losses near the left eye before, showing powdery mud plaster (left) and after cleaning and consolidation of the mud plaster in the losses (right)

And here is an area on the side of the head where I found that some fragments were previously attached in incorrect places. They were repaired long ago (with no documentation) with an adhesive that is soluble in warm water. I reversed the old repairs and found the correct locations for the fragments. I’ve outlined the fragments in their incorrect locations in the before treatment image on the right, below:

Detail of treatment on the side of the head before, with misplaced fragments outlined in pink (left), and after respositioning (right)

Detail of treatment on the side of the head before, with misplaced fragments outlined in pink (left), and after respositioning (right)

I still have lots of work to do before the treatment is complete, but I’m making good progress! I hope to be finished with the treatment early in the new year.

Conservation treatment of Nespekashuti

Nespekashuti has been in the Artifact Lab for several months now and I’m finally ready to say that I’m (almost) finished with his treatment. I say *almost* because I saved one of the most difficult decisions for last – what to do about the gaping hole in his wrappings over his mouth. While I’m not quite ready to take the official after treatment images yet, I am going to post photos of how he looks in his nearly-complete status, along with explanations of what the treatment entailed. (I’ll also admit that posting these things on the blog helps me process my feelings about certain treatments, so thanks in advance for reading.) This post will focus on what I did with Nespekashuti, since I’ve touched on the treatment of his coffin in earlier posts here and here.

Nespekashuti before (left) and after (or nearly complete) (right) conservation treatment

Nespekashuti before (left) and after (or nearly complete, on the right) conservation treatment

Let’s play a little game of spot the difference. I’ll post the image again below, circling areas on the before treatment image that I addressed during the treatment. Some of these things are easy to spot while others are more subtle.

Areas circled in red on the left image show some of the things that I addressed during the conservation treatment.

The red circles on the left highlight areas addressed during the conservation treatment

–  Let’s start from the bottom-up. During my initial examination I noticed that his feet were re-wrapped at some point with what looks like ancient linen. This re-wrapping probably happened before we acquired Nespekashuti in 1893 because in images of him from the Archives, the wrapping around his feet looks the same.

After some poking and prodding of this area, I decided to pull back the newer wrappings around his feet, which revealed this underneath:

Views under the newer linen wrappings from the front (left) and underside (right)

Views under the newer linen wrappings from the front (left) and underside (right)

I can see why someone decided to re-wrap them – the wrappings underneath are significantly deteriorated and darkened, and on the underside, there are some bones exposed. Since we do not know when the newer linen was added (radiocarbon dating might provide more information but it also might not, since it is quite possible that the newer linen is also ancient and could be as old as the original linen) I did not remove it completely. The only change I made in this area was to clean up all of the powdery, deteriorated linen underneath and to encapsulate the damaged wrappings around the feet with nylon bobbinet before putting the newer linen back in place.

– The next three red circles indicate areas where I realigned the linen and removed very deteriorated linen where it was fully detached. I actually did this all over the mummy, but these are areas where it is more obvious. In order to keep the realigned linen in place after making these adjustments, I encapsulated the mummy from his neck to his ankles in nylon bobbinet, toned with acrylic paint to camouflage it.

Preparing to encapsulate Nespekashuti with the nylon bobinnet

Preparing to encapsulate Nespekashuti with the nylon bobbinet

In the image above, you can see the nylon bobbinet draped over Nespekashuti’s body. I secured the bobbinet by tucking it under his body and placing Tyvek-covered Ethafoam blocks in strategic areas between the body and the inside of the coffin (the Tyvek was also toned with acrylic paint to camouflage the blocks).

– The red circle around the amulet on Nespekashuti’s chest is to indicate that I removed it for treatment. The amulet is actually not associated with the mummy at all – it was placed there for exhibition. The amulet is made of faience, dates to the New Kingdom/19th Dynasty, and was excavated from Aniba, Nubia by Charles Leonard Woolley in the early 20th century. It may be replaced for exhibition, but at this point I am not replacing it until our curators have a chance to weigh in.

– Finally, the most obvious part of the treatment is that I made a covering for Nespekashuti’s mouth. I continue to emphasize that the covering is fully removable – it can just be plucked out in pieces with tweezers if necessary. Here is a detail image showing the covering:

Detail of Nespekashuti's head/chest from the left side, after encapsulation and with the mouth covering

Detail of Nespekashuti’s head/chest from the left side, after encapsulation and with the mouth covering

And here is another one from the right side comparing him before and after encapsulation and with the mouth covering:

Nespekashuti before (above) and after (below) treatment

Nespekashuti before (above) and after (below) treatment (click on image to enlarge)

You can see how this all looks from the front in the very first image I posted, but I’m focusing on how he looks from the side since he was previously displayed like this and this is most likely how he will be viewed when on exhibit in the future.

I made the fill by first covering his exposed teeth and surrounding bone with nylon bobbinet, then I layered the exposed area with Japanese tissue paper toned with acrylic paint, and finally I layered some toned bobbinet over the paper. All of the fill materials are tucked into the damaged linen around the loss in this area.

If our curators agree that the treatment is complete and that the fill can be left in place for now, I’ll call the treatment done and finish all of the after treatment documentation. I know that our visitors and readers of this blog were divided on what to do about the mouth, but I think we can all agree that Nespekashuti has received the much-needed care that he deserves. Please write in with any comments or questions you have about any aspect of this treatment! I will be sure to post something on the blog if we make any additional changes, or decide to scrap the mouth covering all together.

A return to the Rubinstein cartonnage

A year ago, I wrote about some cartonnage that we received as a donation from Helena Rubinstein back in 1953. I started working on it but after realizing what a complex project it was going to be, decided to save it for one of our graduate interns to work on (I like to think we save the best stuff for them, and sometimes best = complicated). We didn’t have to wait too long, since this fall we were joined by Eve Mayberger, a 4th year NYU intern who is with us for the academic year, and she was happy to take on the cartonnage as one of her many projects.

One of the reasons the cartonnage is in the lab is because it’s attached to a really ugly old mount, which is no longer providing sufficient support. To remind you, here is what it looked like when it entered the lab:

Cartonnage pieces secured to a wooden mount painted blue

5 separate cartonnage pieces secured to a wooden mount painted blue (before treatment)

Not only do we want to get the cartonnage off of this old mount, but the way the pieces are attached to the mount complicates examination and our understanding of their materials and construction. Basically, this old mount isn’t doing the object any favors, and there’s not much we can do with the object while it’s on the mount.

Eve has spent some time documenting and examining the cartonnage pieces in the Artifact Lab and today she decided to bite the bullet and actually start removing them from the mount. She started with the chest piece (the uppermost piece in the image above). It was secured to the mount primarily through 2 large screws and several smaller nails. Just a few minutes ago, Eve calmly removed the last of the hardware and we were finally able to free this piece from the mount – hurrah!

Eve examining the backside of the cartonnage, recently freed from the old mount, seen on the right side of this photo.

Eve examining the backside of the cartonnage, recently freed from the old mount

Here is a detail of what the back looks like:

View of the reverse of the cartonnage chest piece, after removal from the mount.

View of the reverse of the cartonnage chest piece, after removal from the mount.

Of course now that we can see the other side, we have even more questions about what was done to this piece historically versus what is part of its original construction. Eve will continue to examine this piece and do some more research before beginning the treatment. We will provide updates as she proceeds.

Mysterious bits from Nespekashuti

I’ve written before about mysterious things we’ve found during conservation treatment of our mummies (see this blogpost about the stuff we found at the bottom of Wilfreda’s crate). As I’ve been working on Nespekashuti, I’ve found some puzzling little bits at the bottom of his coffin and caught in his linen wrappings.

Here are a couple piles of detached and in most cases completely deteriorated linen, which needed to be removed as I’ve worked on Nespekashuti:

Piles of deteriorated linen wrappings and other materials removed from Nespekashuti during conservation treatment.

Piles of deteriorated linen wrappings and other materials removed from Nespekashuti and his coffin during conservation treatment.

In these piles, I found the mysterious bits. Some of these things I can recognize, but figuring out exactly what they are and how and why they got there is another story.

Here are some photomicrographs:

Feathers found with  Nespekashuti, 7.5X magnification

Feathers found with Nespekashuti, 7.5x magnification

This first one is easy – these are feathers, of course – little grey plumaceous body feathers from who knows what kind of bird. There are some good resources out there for identifying feathers (see more info at the very bottom of our Learn More! page) but for little feathers like this, and non-experts like me, we need to resort to microscopic analysis by an expert from another institution in order to attempt identification. I did take some photomicrographs of the barbules from one of these feathers, which may be their most diagnostic feature, but again, I lack the experience necessary to make sense of what I’m seeing through the microscope. Just for fun, this is what the barbules look like:

Barbules of one feather found with Nespekashuti, 200x magnification.

Barbules of one feather found with Nespekashuti, 200x magnification.

We also found these:

Bird bones found with Nespekashuti, 7.5x magnification

Bird bones found with Nespekashuti, 7.5x magnification

and this:

Two fused bird vertebrae found with Nespekashuti, 7.5x magnification

Two fused bird vertebrae found with Nespekashuti, 7.5x magnification

These two images above show some tiny bones that were found in Nespekashuti’s coffin. I consulted Dr. Kate Moore, zooarchaeologist and Teaching Specialist in the Center for the Analysis of Archaeological Materials (CAAM). She confirmed that these are bird bones, and the second image shows two articulated bird vertebrae. Dr. Moore told me that upon her initial inspection, she thinks that they may have gone through a digestive tract (think:owl pellets, and that dissection you may have done in grade school!).

And then I found a bunch of this stuff:

Found with Nespekashuti - these look like mouse or rat droppings, 7.5X magnification

Found with Nespekashuti – these look like mouse or rat droppings, 7.5X magnification

These things look a lot like mouse or rat droppings, and there’s little bits of hair caught in some of them. No one said that working on mummies is for the faint of heart!

I also found some bits of cotton, tiny pieces of wood and plant materials, and even some broken glass. We can think of lots of good stories to explain why this stuff would be found with Nespekashuti, but in the end we’re not really sure. Like I said, we are reaching out to some experts about the feathers, so I’ll keep you posted if we learn more – identifying the feathers would be exciting, and could help explain how they got there!

Nespekashuti: aesthetic, ethical, and practical considerations

A shot of me working under the coffin.

The last time I wrote about Nespekashuti, I reported that I was working on stabilizing the painted decoration on the underside of his coffin. I did this with Nespekashuti in his coffin up on sawhorses, and by sitting on the floor to do the work. It wasn’t terribly uncomfortable, but it took a bit longer than I expected, and I’m pleased to say that I’m now finished with this part.

So now I have to turn to the step that I’ve really been putting off – the conservation of Nespekashuti himself. In conservation, we are faced with lots of decisions about the treatment of an artifact. Some of these decisions – whether or not to consolidate flaking or powdery paint, or whether or not to join pieces of a broken ceramic – are (usually) kind of no-brainers. The material choices are often not as simple – we regularly consider and test a wide variety of materials when making treatment decisions – but sometimes even choosing the materials to use is pretty straightforward. For instance, we almost exclusively use the same adhesive (Paraloid B-72) to mend ceramics, no matter where in the world they’re from or how old they are.

But sometimes the trickiest decisions are those that are the most subjective – whether or not to fill a loss for aesthetic reasons, how far to go when treating an object, etc. Fortunately, we rarely make these decisions on our own – we engage our curators, exhibitions team, and other specialists in order to determine a reasonable approach that meets the needs of the desired outcome as best as possible. There are a couple decisions I’ve had or have to make in the treatment of Nespekashuti and his coffin that fall into this category, and I thought I’d lay them out here for consideration (even if I’ve already made my decisions, more or less).

  1. Do I remove Nespekashuti from his coffin for treatment? This was a question I had to ask myself from the beginning. When we removed him from exhibit, I immediately knew that there were some major structural issues with both the mummy and his coffin that needed to be addressed as part of the treatment.
    Overall view of Nespekashuti before treatment, showing torn and deteriorated linen wrappings.

    Overall view of Nespekashuti before treatment, showing torn and deteriorated linen wrappings.

    Normally, when working on a mummy in a coffin, we take the mummy out, and work on both pieces separately. But if I have learned nothing else in my last 3 years in the Artifact Lab, I have learned that there is no such thing as “normal” when working on ancient Egyptian mummies. In Nespekashuti’s case, his remains and wrappings are so deteriorated that we can’t simply lift him out of his coffin without causing significant damage. Another option would be to encapsulate everything and flip the whole package over, and then lift the coffin away from the mummy. This is not out of the question, but I got to thinking, is this really necessary? What do we stand to gain by doing this? We can do all of the imaging we want to do (x-radiography, CT-scanning) with him in his coffin, and the coffin is helping to hold him together at the moment. If we did decide to remove him, how much loss is acceptable?  If we took him out, how easy will it be to get him back inside?  It would be way less than ideal if we couldn’t get him back inside the coffin post-treatment, or if doing so caused more damage. So I have made the decision not to remove him for treatment, and to see if it is possible to work on both Nespekashuti and his coffin as they are. But this is not necessarily a final decision – this is a decision that I’m constantly reevaluating as I carry out the treatment.

  2. And then there is the issue of his teeth.
    A detail of Nespekashuti, showing the damage to the wrappings over his mouth, exposing his teeth.

    A detail of Nespekashuti, showing the damage to the wrappings over his mouth, exposing his teeth.

    Do I cover his teeth or not? I consider this not just an aesthetic issue, but also an ethical one. The damage to the wrappings around his mouth is strange. It is not classic “tomb robbery” damage, which is typically seen on wrappings near the neck or chest, but it does appear to be intentional, at least in part. And certainly, his mouth/teeth were never meant to be exposed like this as part of his burial. Many people who visit the Artifact Lab are fascinated by seeing his teeth – I know there was a dentist in here the other day who was excited to see them. But it also seems to me that many people are somewhat distracted by the teeth – it’s hard to appreciate anything else when those teeth are just staring you in the face. I initially wasn’t thinking too much about this damage – it is quite stable, whereas there are many other areas of the wrappings that are terribly fragile and actively falling apart. And I’ve worked on other mummies with exposed body parts and I have not covered them up as part of the treatment. But I’ve spent quite a bit of time with Nespekashuti and it’s got me thinking – what responsibility to we have to him, and to the preservation of his remains, wrappings, and his burial? How do we want him to look when he goes back on display? This is not just my decision to make, but I have decided that it is my responsibility to provide an option – so I am planning to create a removable covering for the mouth, which I will present to our curators post-treatment. I like the idea of covering his mouth, but I will emphasize the fact that this covering will be removable, therefore, reversible. I haven’t made the covering yet, but I will certainly post some images once I do.

I’m curious to hear the opinions of others, so if you have thoughts about these questions and decisions, and any other considerations, please post them in the comment section below.

The right tools for the job

I often think about how a successful treatment depends on having the right tools and materials for the job. Here are some of the things that I have in front of me almost at all times in the Artifact Lab, and I use for many of the treatments I work on:

Tools labeledI’ve labeled them in the image, and I’ll list them below:

1. Silicone-release Mylar. This is Mylar film coated with silicone, which provides a non-stick material that is perfect for certain applications – I’m currently using it as a barrier between a painted surface that I’ve consolidated and the weight I’m applying to hold the area in place. The silicone-release Mylar prevents the area I’ve treated from sticking to the weight.

2. Weights of various sizes (and weights). This one (pictured above) is a favorite because it is so cute and looks like a Hershey’s kiss. It is made by our creative colleagues at Inherent Vice Squad. Check out their website by following this link: Don’t look drab in your lab!

3. Insect pins. These are very fine straight pins, which I often use to hold linen in place when carrying out treatment on mummies. At the moment, they are also coming in handy to unclog my syringe as I work on the treatment of Nespekashuti’s coffin. See this blogpost to read more about how these pins can be used. Okay, and just because I love the Inherent Vice Squad, and because these are called insect pins, I must also tell you that if you’re looking for a way to store your pins, you should check out their rad Museum Pest Voodoo Doll pincushions. I have no good excuse for not picturing one above, but I do have one for my sewing supplies at home.

4. Syringes with specialty tips. The two pictured here have two different types of tips: a narrow metal tip and a flexible plastic tip. The flexible plastic cannulae are especially useful for areas that are sensitive to abrasion or are difficult to access.

5. Fine-tipped brushes for consolidation and inpainting. I do a lot of work on painted surfaces, and often need to apply very small amounts of adhesive along cracks and under paint flakes (see video footage of paint consolidation here). We order our brushes from Blick.

6. Colour Shapers. I had never worked with Colour Shapers until I started working at the Penn Museum. I find these tools, which have a rubber composite tips of varying sizes, shapes, and degrees of firmness, especially useful for paint consolidation.

7. Fine-tipped tweezers. A good pair of fine-tipped stainless steel tweezers/forceps is a staple in a conservator’s toolkit. I was fortunate to get to keep the tweezers I was given to use in graduate school, and I use them daily in the Artifact Lab.

8. Stainless steel micro-spatula. Ditto my comment about fine-tipped tweezers above.

9. Scalpel handle. Ditto.

10. Small, sharp scissors. A third ditto.

11. Bone folder. Bone folders are made of bone (usually cattle) and are often used in conservation for making storage supports, folders, and handling trays – they provide just the right edge for scoring lines and creasing board and paper.

12. Bamboo (or wooden) skewer. We use bamboo skewers for all sorts of things in the lab. Their #1 use is probably for making cotton swabs but we also use them to clean objects, to fashion clamps and apply pressure to objects when carrying out treatment…and a whole host of other things. See this great blogpost on the Phoebe Hearst Museum of Anthropology’s blog to read about some examples.

13. Porcupine quill. I had heard about porcupine quills being used in conservation treatments but I had never had the chance to try one until a former Penn Museum intern gave me a porcupine quill as a gift a few years ago. We often have to scrape corrosion and compacted soil off artifacts and sometimes a porcupine quill provides just the right pressure without damaging the surface of an object. And not surprisingly conservators have found other uses too – see this blogpost for one example.

I’ll be interested in hearing if anyone reading this has a favorite tool or material – or supplier! Leave a comment here if you do! Oh, and one last plug for the Inherent Vice Squad: if you’re looking for a nice way to store or carry your tools, check out their really beautiful tool wraps and stand-up tool caddies.

High tech/low tech

We often talk about how we try to take advantage of new technologies whenever possible as part of the conservation examination and treatment of objects. It’s those new technologies that help us continue to learn and do more with objects that we have had for 100+ years. For example, even though x-ray radiography has been around since the late 19th century (see this image of the first radiograph ever captured in 1895) there have been major advances since then, including the development of computed tomography (CT-scanning) and digital radiography, so we frequently re-image objects that were x-rayed in the past to capture even more details (see this blogpost to see the recent radiographs we captured of our mummy Nespekashuti).

There are also many other new technologies that we use on a regular basis (at least in some instances), including our portable x-ray fluorescence analyzer (pXRF), our Mini-Crimescope, our Lynton laser cleaner, just to name a few.

Ron Almagno, a Forensic Instruments Specialist, shows our department some of the features of our Mini-Crimescope.

Ron Almagno, a Forensic Instruments Specialist, shows our department some of the features of our Mini-Crimescope.

But there are just as many, if not more, instances when the low-tech method or solution makes the most sense and gives the best, or just as satisfactory, results. I can provide many examples of this, but the latest low-tech approach that I’m taking in the Artifact Lab is figuring out how to examine and work on Nespekashuti and his coffin base.

I decided to tackle the treatment of Nespekashuti’s coffin before dealing with his remains. After working on all of the areas I could reach while it was sitting on a table, I realized that I needed access to the underside of the coffin. When I’ve worked on the back of other coffins, I first work on the exposed side and then flip the coffin over and work on the back (see a previous blogpost (including video footage!) Flippin’ coffins). The only problem with Nespekashuti and his coffin is that he is still inside, and I’m not ready to take him out yet (or ever…more on what I’m thinking about how to best preserve his remains in a future post). So, the best way to get at the underside was to put the coffin up on sawhorses, padded with Volara polyethylene foam.

Nespekashuti in his coffin up on sawhorses in the Artifact Lab.

Nespekashuti in his coffin up on sawhorses in the Artifact Lab.

This immediately allowed me to see some of the painted decoration on the underside, which I had never seen before:

Detail of the back of Nespekashuti's coffin

Detail of the back of Nespekashuti’s coffin

I’ll work on the areas that are exposed and then I can move the sawhorses around to document and work on the areas that are obscured at the moment.

I’ve started to stabilize the flaking gesso, lifting linen, and paint in the areas I can access, and I’m securing these areas while they dry with plastic wrap, silicone-release Mylar, pieces of Volara foam, archival board, and weights.

Detail of an area being secured with plastic wrap, foam, archival board, and weights.

Detail of an area being secured with plastic wrap, foam, archival board, and weights.

So there is nothing high-tech about what I’m doing with Nespekashuti in the lab at the moment, BUT the treatment will eventually allow us to do more high-tech things with him, like CT-scanning, multispectral imaging…and anything else that we can gain access to that may help us learn more about him.

 

A closer look at our stola coffin lid

In my last post about this late 21st/early 22nd stola coffin lid, I referred to it as eye candy.

Overall before treatment image of the stola coffin lid, L-55-16B

Overall before treatment image of the stola coffin lid, L-55-16B.

This coffin is beautiful, and we could discuss how nice it is to look at all day. But in this post, I’m going to focus on some of the more subtle, somewhat less-attractive (but perhaps even more interesting) features that I’ve discovered about this coffin lid as I’ve begun to work on it. In fact, on Friday I spent awhile discussing some of these details with a group of conservators and interns from the Philadelphia Museum of Art (PMA). As I mentioned in my last post, although this coffin has been on long-term loan to us since the 1930s, it still technically belongs to the PMA, so I am carrying out my treatment in close consultation with one of their objects conservators.

Penn Museum conservator Alexis North (far right) discusses a cat mummy with the PMA conservators and interns.

Penn Museum conservator Alexis North (far right) discusses a cat mummy with the PMA conservators and interns.

I always appreciate the opportunity for professional exchange, and I was happy to be able to discuss my plan, including materials and approaches with them. This discussion energized me to get started with the treatment, and that is exactly what I did, almost as soon as they left.

One thing that I noticed in my initial examination is that this coffin lid has been worked on before. There are residues of old adhesives in areas, including an adhesive mixed with a sawdust-like material, especially around the foot of the coffin.

Adhesive residues on an area of exposed wood.

Adhesive residues on an area of exposed wood near the foot.

I have seen these same types of repairs on at least one other coffin in our collection, and while there is no documentation of them, I am suspicious that this treatment was carried out in our museum soon after we acquired this coffin, but long before our conservation lab was established 49 years ago.

The foot of the coffin has another type of repair as well – there are 2 brackets that are held on with screws on the underside of the foot, apparently to secure some of the wood components. This whole area moves when handled, so the brackets and screws will have to come off so that I can better assess what is going on.

Detail of the foot of the coffin, showing the brackets used in an old repair.

Detail of the foot of the coffin, showing the brackets used in an old repair.

There is some very powdery material associated with areas of damage, especially on the face, which appears to be partially due to deterioration of the mud plaster, but also may be due to insect activity. I’ll have to investigate this further over the course of the treatment.

Detail of the powdery material near the left eye.

Detail of the powdery material near the left eye.

And then there are some materials included in the mud plaster, including some course linen threads and even a leaf, which I am documenting as I work to clean the surface.

Detail of a detached piece of mud plaster with linen thread inclusions.

Detail of a detached piece of mud plaster with coarse linen thread inclusions.

L-55-16B_detail7

Detail of an area of damage, which exposes a small corner of what appears to be a leaf caught in the mud plaster.

The next time I post images of this coffin lid, it should be a lot cleaner, as I plan to complete the initial surface cleaning within the next week. More soon about this, and other observations and developments in the treatment.

 

Treating Nespekashuti’s coffin

Many of you may be wondering about Nespekashuti, our New Kingdom mummy whose remains are quite a jumble under his wrappings. As you can imagine, Nespekashuti is presenting some interesting conservation challenges for us. So far I have focused on surface cleaning and trying to understand the extent to which his linen wrappings are damaged. I decided that before I can deal with stabilizing Nespekashuti any further (and making the decisions necessary to do this), I need to address the damage to his coffin.

Overall view of the proper left side of Nespekashuti's coffin (before treatment)

Overall view of the proper left side of Nespekashuti’s coffin (before treatment)

Nespekashuti’s coffin is quite interesting. I’ve only been able to examine the lower half (which he is contained in) so far. It is made of several pieces of wood doweled together, followed by coating with gesso in areas, then the exterior surface is entirely covered with a single layer of linen, which was coated with gesso and painted, and then finally varnished, likely with pistacia resin. Overall, the painted surface of the coffin is in great condition. But there are some structural concerns, including breaks in the wood, separation and movement between different pieces of wood, and separation of the linen, gesso, and paint from the wood substrate.

Detail of the exterior foot of the coffin, showing separation of the linen, plaster, and paint from the wood.

Detail of the exterior foot of the coffin, showing separation of the linen, plaster, and paint from the wood.

Detail of damage on the proper left side of the coffin.

Detail of damage on the proper left side of the coffin.

I’m starting out my treatment by readhering areas where the linen is lifting away from the wood and plaster below. To repair these areas, I’m using a tried-and-true combination of methyl cellulose, methyl cellulose bulked with glass microballoons, and Japanese tissue paper.

Treatment in progress - I'm using clamps to hold areas in place while the adhesive dries.

Treatment in progress – I’m using clamps to hold areas in place while the adhesive dries.

During treatment - image detail showing the same area at the foot of the coffin (seen before treatment in the second image in this post).

During treatment – image detail showing the same area at the foot of the coffin (seen before treatment in the second image in this post).

This is just the beginning! Once I finish working on the areas I can access, I’ll have to move the coffin to a support that allows me to access the underside/back, so that I can better evaluate and treat those areas as well.

Exploring the painted surface of three coffin fragments

Last week, I wrote about x-raying the fragments of a painted wooden coffin, as part of the conservation treatment. The radiographs helped us see what is under the painted surface. We then turned to the painted surface itself. Through cleaning, we revealed how beautiful and well-preserved the decoration is. I described the cleaning process (and linked to a short video showing the process!) in a previous post.

E12617beforeaftercleaning

E12617A-C coffin fragments before (left) and after (right) cleaning

While it was impossible to see the full range of colors on the boards before cleaning, after cleaning we could see that there were several different colors used to decorate the surface, including two different yellows, red, green, black, and paint that appears black but where it is abraded/damaged looks blue. After much experience working on ancient Egyptian painted wooden artifacts, I knew enough to suspect that some of the paint that appears black is actually Egyptian blue.

It appears that there is a lot of black paint here, but not all of this paint was originally black. The yellow arrows point to black paint while the red arrows point to areas that I believe were originally blue.

It appears that there is a lot of black paint here, but not all of this paint was originally black. The yellow arrows point to black paint while the red arrows point to areas that were originally blue.

If you’ve been reading our blog, you are probably very familiar with one of our favorite photography techniques for Egyptian material, visible-induced infrared luminescence imaging. I have written about it previously, where I explain the process and the equipment we use (follow this link to the post).

Sure enough, it worked beautifully to confirm, and to allow us to see the Egyptian blue on this object:

E12617normaIRfalsecolor

Image of the coffin boards in normal light (left), Visible-induced infrared luminescence image (center), False color image (right). Click on the image to see a full-screen version.

All of the darkened/altered Egyptian blue shows up as bright white in the center image above, and the red areas in the false color image on the right help to further visualize where the blue is in relation to the rest of the painted design. Gotta love this technique!

So that’s great for determining the presence and location of Egyptian blue. But what about some of the other colors? I was particularly curious about the two different yellows and the green. In the case of the yellows, are they two different pigments? And as for the green, which pigment(s) were used to produce this color? Without (for the moment – more about that later) knowing the exact time period of this object, I knew there could be at least a couple different options, including Egyptian green (or green frit), and green earth.

To gather more information about these pigments, I carried out portable x-ray fluorescence analysis (pXRF) in select areas on the boards. I collected data from the following areas, marked with colored X’s in the image below:

pXRF analysis locations, with elements detected listed in order of peak height, from large to small

pXRF analysis locations, with elements detected listed in order of relative peak height, from large to small

As you can see, I labeled the image with the findings from the pXRF analysis. It looks like the two different yellows are indeed two different pigments: the darker, more orange-yellow paint contains primarily calcium and iron, suggesting that this is an ochre, while the brighter yellow paint contains calcium, arsenic, and iron. The relatively large amount of arsenic suggests that this yellow was produced using orpiment (arsenic sulfide).

The green paint also contains arsenic, as well as calcium, copper, and iron. So it appears that the green was produced by mixing an arsenic-containing material (orpiment?) with a copper-containing pigment. Due to the lack of any visible-induced IR luminescence in the green areas, I don’t think that these areas could contain any Egyptian blue, so perhaps the green was made by mixing orpiment with Egyptian green. And as you can see, the blue paint does not contain any arsenic, but does contain calcium, copper, and iron, which we expect to find in areas painted with Egyptian blue. Further analysis will be necessary to determine exactly which pigments were used in the yellow and green areas, but we have discovered a lot using these completely non-invasive techniques!

In my next post about this object, I hope to write about the translation and interpretation, for which I’ll need to consult with the museum’s Egyptologists. In the meantime, if you’d like to learn more about green pigments on ancient Egyptian objects, and more applications of multispectral imaging on Egyptian objects, check out this really great video presentation by Kelsey Museum Conservator Carrie Roberts (originally presented at the 2014 ASOR Annual Meeting):

Green Pigments: Exploring Changing in the Egyptian Pigment Palette from the Late to Roman Periods through Multispectral Imaging and Technical Analysis