Glowing in the dark: multispectral imaging and Egyptian blue

There is something I’ve mentioned before on this blog, but never actually shown, and that is the ability to “see” Egyptian blue on objects using multispectral imaging. On many objects Egyptian blue is very well-preserved, so there is no need for special examination techniques in order to spot it. But there are cases in which being able to accurately identify this pigment is important. Sometimes Egyptian blue deteriorates either by changing color (to green or black) or by becoming lost altogether, making it difficult to know which areas may have originally been blue, or if blue was used at all.

And then there are objects like this one:

Front view of the shabti box in normal lighting conditions

Front view of the shabti box in normal lighting conditions

You’ve seen it before, it’s our painted wooden shabti box. I have been working on the treatment of this box for awhile now, mostly to stabilize the flaking paint and varnish. And this thick, orange-yellow varnish, which we believe is original, and is pistacia resin, makes it difficult to see the painted surface, both the details and the colors. While I could see that there is some green and possibly blue paint on this box, between deterioration of the paint and/or pigment, and the thick application of pistacia resin, I couldn’t say for sure which areas may have originally been painted blue…until now…

Taking advantage of the fact that Egyptian blue has luminescent properties when illuminated with visible light and captured in infrared, we can detect where Egyptian blue was applied. And wow, look at these results:

Visible-induced IR luminescence image of the shabti box. Light source: SPEX Mini Crimescope with 600nm band-pass filter. Captured with a Nikon D5200 modified camera with an IR 87C filter.

Visible-induced IR luminescence image of the shabti box. Light source: SPEX Mini Crimescope with 600nm band pass filter. Captured with a Nikon D5200 modified camera with an IR 87C filter.

This is the same surface of the shabti box seen in the first photo, but zoomed in a bit, and taken under different lighting conditions and captured with a different camera. The areas that appear white are where Egyptian blue was applied. Because everything else pretty much disappears on the box in this image, to better visualize where the Egyptian blue is in relation to other details, we created a false-color image in Photoshop:

False color image of the shabti box. The areas painted with Egyptian blue appear red.

False color image of the shabti box. The areas painted with Egyptian blue appear red.

In this false color image, the areas that appear red are where the Egyptian blue was applied. It’s not perfect (you can see that the bands in the hair of the figure on the right don’t really show up) but we could play around with the photographs a bit to improve this.

We did this imaging on all surfaces of the box, and on the box lids. Here is a regular photo, a visible-induced IR luminescence photo, and a false color image of one of the box lids, also showing lots of Egyptian blue:

Shabti box lid, normal light

Shabti box lid, normal light

Visible-induced IR luminescence photograph

Visible-induced IR luminescence photograph (areas in white = Egyptian blue)

False color image (areas in red = Egyptian blue)

False color image (areas in red = Egyptian blue)

You can use any regular/visible light source to produce the luminescence, but in this case, we used our fancy-schmancy new Mini Crimescope, which was developed for forensic work, but is useful to us because it allows us to examine objects under specific wavelengths of UV and visible light. We found that using a 600nm bandpass filter worked best for capturing the IR luminescence of the Egyptian blue.

In order to “see” the luminescence, we have to capture images using a modified digital camera, with an 87C IR filter.

In summary, we’re having lots of fun with our new equipment, and finding that these Egyptian objects are perfect subjects for learning how to use the Crimescope and the modified camera, because they produce such great, dramatic images.

 

I spy with my little eye…

A long time ago I posted an image of our Mummy Gallery, circa 1930s. Well, I find myself returning to this photograph again and again as I work on new objects in the lab.

The "Mummy Room" ca. 1935

The “Mummy Room” ca. 1935

Can you find two of the objects that we’re working on right now, the beautifully preserved painted wooden coffin and the shabti box and shabits, all from the New Kingdom? Here are images of these objects, just to help you out:

Overall view of the interior of the coffin from above

Overall view of the interior of the coffin from above

The shabti box and one of its associated shabtis

The shabti box and one of its associated shabtis

Did you find them? I’ll post the image of the mummy room below, with these objects circled in red.

mummy room with coffin and shabtis circledAnd here is a cropped version of this image, to better show these objects:

31011_mummyroom_1935-croppedWhile it’s just cool to see an image of these objects in a previous display, it’s also helpful to me as a conservator. I can see how they were mounted for exhibit (the coffin is standing upright, the shabtis are on little platforms) and I can also get a sense of condition at this time (for instance, the middle lid of the shabti box is missing in this image, and I can see some losses to the painted surface as well).

I’m am nearly finished working on the shabti box and shabtis, and the coffin will also be completed this year, so we will finally be able to put these objects back on exhibit.

Coming up next week, I will be posting some multispectral images of the shabti box and shabtis, which is helping us better understand the original colors and also to see some of the painted details, which are now largely obscured by the orange pistacia resin varnish.

 

Consolidating a painted wooden shabti

This one-minute video captures what I did at work today, times about 250.

Shabti paint consolidation (click on the link to view the video)

To put it into context, I was working on this painted wooden shabti, which I’ve mentioned on the blog before.

The area blocked out in yellow is the area I'm working on in the video.

The area blocked out in yellow is the area I’m working on in the video.

Here is a still shot of the area I’m working on in the video, taken at 10x magnification using our binocular microscope:

IC800006The paint is actively flaking in many areas on this object. In the video, you can see me applying a 2% solution of methyl cellulose in water by brush to a loose flake of paint, and then after allowing the flake to relax, tapping it into place using a silicone colour shaper. It’s slow-going, but it’s working!

 

Sizing up our child mummy

Everyone loves Tanwa, our child mummy, but a lot of people ask about her size. “Isn’t she kind of small for a 5-year-old?” they’ll ask. Without knowing a whole lot of 5-year-olds myself, I usually say, yes, I guess, but you have to remember that she’s wrapped really tightly and that people were generally smaller in stature 2000 years ago. We also don’t know how she died, so theoretically, her size could have been affected by a disease or something that eventually caused her to die. But the truth is, I don’t know how she compares to the size of kids today.

But today I had the perfect opportunity to size her up, and a willing subject, my niece Luisa. Luisa is “almost 4-years-old” (this is a direct quote). We held Luisa up next to Tanwa for a little height comparison.

luisa and tanwaLuisa is the tallest in her class and she’s “almost four”, and she’s just about the same height as Tanwa. So I would say that Tanwa isn’t so short after all. What do you think?

 

Views inside a painted wooden coffin

It is impossible not to see this object when you enter the Artifact Lab, as it’s front and center, and immediately impressive, due to its well-preserved painted details:

view of lab with coffin with arrowThis is the lower-half of a late New Kingdom painted wooden coffin, that recently came up to the Artifact Lab. Our visitors are always commenting on how vibrant the colors are, and that is mostly based on what they can see from the exterior. But the interior of this coffin is fully decorated, and arguably even more impressive, and I promised some people this week that I’d post photos of the interior soon. Here they are:

Overall view of the interior of the coffin from above

Overall view of the interior of the coffin from above

coffin right side

View of the right side

coffin left side

View of the left side

View of the interior, top of the coffin

View of the interior, top of the coffin

The only areas on the coffin that are not decorated are the exterior of the back, and both sides of the foot/base.

All in all, this coffin is in great condition, but it needs some treatment, including surface cleaning and stabilization of the wood and paint in some areas.

There are also a few mysterious things about it, in particular, these drilled holes in the back – what the heck are these all about?

There are 8 rows of holes drilled through the back of the coffin

There are 8 rows of holes drilled through the back of the coffin

Stay tuned as we investigate further.

 

Exploring Villanova’s new CAVE

Today was the launch of the Villanova CAVE. I’m a little confused about what CAVE stands for because in the opening remarks someone mentioned that it is “computer assisted virtual environment” but in all of the promotional materials about the CAVE it says that it stands for “CAVE automatic virtual environment”. In any case, it’s an 18′ x 10′ x 7.5′ high room with a configurable ceiling, where, with a pair of special glasses, you are immersed in a virtual experience, which could mean exploring areas closed to the public in Eastern State Penitentiary, walking through a plaza in Mexico, or looking inside a falcon mummy. And not just any falcon mummy, OUR falcon mummy, which is why I was at the opening today.

Dr. Frank Klassner giving the opening remarks at the Villanova CAVE opening

Dr. Frank Klassner giving the opening remarks at the Villanova CAVE opening

We found out about the CAVE several months ago, thanks to Dr. Michael Zimmerman, who introduced Lynn Grant and I to his colleague Dr. Frank Klassner. Dr. Klassner is the director of the CAVE, and is also a professor of Computing Sciences and director of the Center of Excellence in Enterprise Technology (CEET) at Villanova. Dr. Klassner was looking for collaborators who might be interested in exploring objects, places, or spaces using the CAVE. We had recently CT-scanned our falcon mummy, and offered to share that data with him.

After the opening remarks, we were allowed to enter the CAVE in groups of 15, where we put on the special glasses (which looked a lot like the 3D glasses you get in a movie theater) and we were shown some demos of the potential applications.

A glimpse inside the CAVE (we weren't really supposed to take pictures, not that they could really capture what we could see with the glasses anyway)

A glimpse inside the CAVE (we weren’t really supposed to take pictures, not that they could really capture what we could see with the glasses anyway)

They didn’t show the falcon mummy in my group, so I pulled the guy leading the demo aside (who turned out to be George Lacakes, Director of the Virtual Reality Laboratory at Rowan University), and put in a special request for the falcon. George told me that they hadn’t totally finished processing the CT-data because it needed a lot of work, so we couldn’t fully unwrap the falcon in the CAVE just yet, but we were still able to look at a portion of it (the CT-scan was captured in 2 different sections, so we were only looking at one) and peer inside to see the skeletal remains. I told Dr. Klassner that we’d just have to make a trip back once they finished processing all of the data, and he enthusiastically welcomed a return visit.

A section of the falcon mummy, viewed on George Lacake's computer, just to give you an idea of what the image looks like.

A section of the falcon mummy, viewed on George Lacakes’ computer, just to give you an idea of what the image looks like.

In addition to being able to explore objects and places through previously-captured data, the CAVE has a rover named Seymour (get it? because it helps you see more) which can capture images anywhere (like an archaeological site or the galleries of a museum) that can then be explored in the CAVE.

The development and construction of the CAVE was supported by a grant from the National Science Foundation. Watch a time-lapse video of the CAVE being constructed, and read more about the CAVE here.

 

More on Madame Rubinstein

Helena Rubinstein built her life and her wealth on beauty, so it should come as no surprise that she was attracted to this stunning Ptolemaic cartonnage funerary mask and it’s related pieces, which we are working on in the Artifact Lab.

Rubinstein was known as a great art collector (she bought pieces by the truckload, according to this article in the New Yorker) and she decorated her many homes with modern art, as well as artwork and antiquities from all over the world (she amassed an especially large collection of African art). When I found out that these cartonnage pieces in our collection had once been in the possession of the Madame, as she preferred to be called, I was hoping that I’d be able to find a photo of them on display in one of her homes.

Rubinstein, photographed in 1951, with some selections from her Africa and Oceania collection on display

Rubinstein, photographed in 1951, with some pieces from her Africa and Oceania collection. Image from “Over the Top: Helena Rubinstein: Extraordinary style, beauty, art, fashion” by Suzanne Slesin, 2003.

While I found many photos showing the interior of her homes, I didn’t catch a glimpse of the funerary mask in any of them. And it’s possible that she never had it, or the rest of the cartonnage, on display at all.

Based on letters found in our Archives, I found out that we ended up receiving these pieces as a gift from Mme. Rubinstein through the Carlebach Gallery in New York. The gallery owner, Julius Carlebach, acted as the intermediary for the donation, which was given to the museum while Dr. Rudolf Anthes was Curator of the Egyptian Section, under the directorship of Froelich Rainey. In his letter offering the cartonnage pieces to the museum, Carlebach noted that he was sorry that Madame Rubinstein had no further information about them.

But I did find something interesting in Froelich Rainey’s thank you note to Mme. Rubinstein.

UPMAA_Rainey_Page_2The letter is a little confusing because he refers to the mask as a mummy portrait, but I’m sure he’s talking about the cartonnage. As you can see, he mentions that the lower section would be included in the museum’s television program “What in the World”. “What in the World” was a Peabody Award-winning television program, where Rainey moderated a panel of experts trying to identity artifacts, while viewers were given clues to the answer (it ran for 14 years and by the early 1960s it was one of the oldest programs on television!). The episode featuring the cartonnage aired on May 23, 1953.

Unfortunately, as far as we know, only a few episodes of this show have survived, not including this 1953 episode. Those that we do have are now digitized and on the museum’s YouTube channel (follow this link to view them). Is there any way we might be able to find the one featuring Mme. Rubinstein’s gift? It seems unlikely, but I’d love to think that it is possible.

In the meantime, we’ll be doing our own investigations on these pieces right here in the Artifact Lab, and we’ll report on the blog as we learn more and make decisions on treatment.

Special thanks to Alex Pezzati, our Senior Archivist, for his help in locating these documents.

 

A gift from a late, great, beauty magnate

Some of the newest objects to come into the Artifact Lab are pieces of cartonnage which are related to this beautiful funerary mask, currently on exhibit in our Upper Egyptian gallery:

53-20-1A A funerary mask made of gilded cartonnage, currently on display in our Upper Egyptian gallery.

53-20-1A A funerary mask made of gilded cartonnage, currently on display in our Upper Egyptian gallery

Here are the pieces of cartonnage currently in the lab:

53.20.1bt01_compAnd here is a detail of the chest covering, adhered to fine linen with a black resinous material:

53.20.1bt03_chestcoveringAll of the pieces are unfortunately nailed down to the painted wooden (contemporary) support below. I’ve been working on documenting the cartonnage and getting the nails out, so that I can better evaluate the condition of these pieces.

I also have been doing some background research on these pieces, and found that, unlike most of the objects that I work on in the lab which are from excavations or which were collected early on in the museum’s history, this cartonnage assemblage was donated to us by cosmetics magnate Helena Rubinstein. Rubinstein, who is known for her wildly successful brand of cosmetics, and who, when she died, was one of the world’s richest women, was also an art collector. I’m not sure exactly how she wound up buying these pieces and then how they ended up here at the museum, but I’m heading over to the Archives now to see what I might learn there. More on this soon!

 

 

Conserving a 6500 year-old skeleton from Ur

No, he’s not Egyptian, and no, he’s not a mummy, but somehow this 6500 year-old skeleton made his way into the Artifact Lab, and we are working on conserving his remains.

Thanks to recent media attention, he has drawn visitors to the museum, hoping to catch a glimpse of him. Fortunately for our visitors, he is on view In the Artifact Lab every day the museum is open, until we complete the conservation treatment, which will be sometime in the next few weeks.

Just to give you an idea of what you might see if you visit the lab in the upcoming weeks, here are some photos taken by Phil and Diana Monslow, a Welsh couple who visited the museum on Thursday and promptly emailed their photos to us that same day.

Conservators Tessa de Alarcon and Nina Owczarek working on the Ubaid skeleton

Conservators Tessa de Alarcon and Nina Owczarek working on the Ubaid skeleton (with an Egyptian coffin from the New Kingdom in the background)

skeletondetail

A detail of the remains from the side, showing wax on the surface, soil, and burlap (modern, used to help lift the fragile remains from the site) below

Another shot of Nina and Tessa working on cleaning, mending, and consolidating the fragile remains

Another shot of Nina and Tessa working on cleaning, mending, and consolidating the fragile remains

Thanks Phil and Diana for your great shots!

 

Conserving Egyptian Collections, day 2

Day 2 of Understanding Egyptian Collections at the Ashmolean featured 11 speakers (including myself), and the papers covered a wide range of topics.

The front entrance of the Ashmolean Museum

The front entrance of the Ashmolean Museum

I didn’t take any photos during the talks, so I have less visual content to share for this post. For ease of sharing the information about the presentations, I’m going to list the talks here, with speakers names, titles, and brief remarks (all of the talks over the 2 days deserve way more attention than I give them here and in my previous post – hopefully a publication will result – see more about this below). Several of the talks had co-authors, but I’m only listing the co-authors names if they were present at the meeting.

  • “Evolving Attitudes: past and present treatment of Egyptian Collections of the Oriental Institute.” Alison Whyte, Associate Conservator, Oriental Institute. Alison shared many old archival photos which have helped conservators understand old restorations, and make decisions about how to revisit the conservation of objects that have been in their collection for a long time. Alison also shared the project of the guest curator Rozenn Bailleul-LeSuer of the special exhibit “Between Heaven and Earth – Birds in Ancient Egypt“. Rozenn’s work included CT-scanning and making a 3D print of an eagle mummy, and 3D replicas of its skeletal remains. She brought a 3D print of the eagle mummy to show us, but unfortunately it got lost on her way to the conference along with the rest of her luggage! Let’s hope that it eventually turns up.
  • “Mummy case saved by LEGO: a collaborative approach to conservation of an Ancient Egyptian cartonnage.” Sophie Rowe, Conservator, and Julie Dawson, Senior Assistant Keeper, Conservation, Fitzwillliam Museum, University of Cambridge. LEGOI was familiar with this project due to the fact that it was prominently featured in the news last year. This project was a collaboration between conservators and engineering student David Knowles, who designed a structure to support a cartonnage coffin upside-down during treatment, and devised a plan to use LEGO structures to provide long-term support for the coffin from the interior. To the right is an image of the LEGO structure (it looks a little different from the LEGOs we’re all familiar with).
  • “The importance of technical analysis and research for the conservation and display of archaeological garments.” Anne Kwaspen, Conservator of the Archaeological Textile Collection, Katoen Natie. I had never heard of Katoen Natie before – it is a company based in Antwerp that has invested in collecting art, through a program called HeadquARTers. They have a collection of archaeological textiles from the art market and private collectors. Anne discussed the study and conservation of their Egyptian wool and linen tunics, and their approach to display.
  • “Problems and possibilities for the Petrie Museum’s pottery display.” Susanna Pancaldo, Senior Conservator, UCL Museums and Collections. Susanna spoke about recent upgrades to the pottery room at the Petrie Museum. Their pottery room has approximately 3400 objects on display in 36 cases, and was suffering from issues with light, extremes in relative humidity and temperature, lack of mounts and damaging mounts, lack of space, and outdated/minimal labels. In 2014 they received funding to make improvements, including new lighting, new interpretive information, the addition of an introductory showcase showing Petrie’s sequence dating technique, and to carry out conservation surveys and treatments, among other things.
  • “Innovations for the display of Dynastic textiles using existing designs at the Metropolitan Museum of Art.” Emilia Cortes, Conservator, Metropolitan Museum of Art. Emilia’s presentation focused on the remounting of Egyptian textiles on exhibit to allow for easier access. She showed how she was able to modify existing mounts for elaborate, intricate objects, including this incredible floral collar from Tutankhamun’s embalming cache. Her retrofits included the innovative use of food-grade silicone for preventing movement of objects on exhibit.
  • “King Menkaure in Motion: the metamorphosis of a Monolithic royal sculpture from the Old Kingdom.” Susanne Gansicke, Conservator, Museum of Fine Arts, Boston. Susanne described the monumental task of moving their King Menkaure statue from one gallery to another within the Museum of Fine Arts. With 2 years lead time, they were able to do gamma radiography of the sculpture in the gallery to help prepare and make decisions about the move, which involved setting the statue on a lifting frame, with 12 wheels attached, and then moving it with the assistance of 2 lifts. It was a very thoughtful project and an impressive feat!
  • “On not exhibiting a corpse: the Mummy Chamber, Brooklyn Museum.” Lisa Bruno, Head Objects Conservator, Brooklyn Museum of Art. In preparation for the museum’s new “Mummy Chamber“, conservators at the Brooklyn Museum worked on 2 unwrapped mummies, Pa-seba-khai-en-ipet and an anonymous man. The anonymous man, who was methodically unwrapped in the late 1950s, with the procedures documented in the book Wrapped for Eternity, was rewrapped in the conservation lab for display. The decision was made not to display the remains of Pa-seba-khai-en-ipet due to his poor condition, and ultimately, because displaying his remains would mean displaying a corpse, not a mummy.
  • “Reflecting on Egyptian Pigments: the use of Fibre Optic Reflectance Spectroscopy (FORS) for pigment analysis at the Fitzwilliam Museum.” Jennifer Marchant, Antiquities Conservator, and Abigail Granville, Pigment Analyst, Fitzwilliam Museum, University of Cambridge. Jennifer and Abigail discussed their use of FORS to analyze pigments using a FieldSpec 4 spectroradiometer, which measures in the UV/visible/near IR range. They are building their own reference library, and finding that it is useful as an initial non-invasive examination method, and may be used in the examination of varnishes and binding media as well.
  • “A case for keeping: the life and afterlife of ritual metal statuary in Ancient Egypt.” Deborah Schorsch, Sherman Fairchild Center for Objects Conservation, Metropolitan Museum of Art. Deborah spoke about examples of Egyptian metal statues in collections around the world that show evidence of reworking for various reasons, often for the purpose of the object serving a new ritual function, or removing details in order to retire objects. One example she spoke about at length was the copper and gold Hierakonpolis falcon in the Egyptian Museum in Cairo. This statue had 4 different phases, with new material being added in each phase of its life.
  • “Bringing it all together In the Artifact Lab: Conservation, research, display, interpretation.” (Me! I spoke about working on Egyptian material and mummies in a public space, and some of the unique interactions and investigations that we have carried out as a result of the working environment.)
  • “Ancient Worlds: Open data, mobile web, haptics, digital touch.” Stephen Devine, Digital Communications Officer, and Sam Sportun, Collection Care Manager/Senior Conservator, Manchester Museum. Stephen and Sam introduced us all to Haptic technology and how it is being used at the Manchester Museum to allow visitors to “handle” artifacts. They also spoke at length about the importance of mobile technology and the development of an app to allow visitors to explore and provide feedback about their Ancient Worlds exhibit.

Ashmolean Head of Conservation Mark Norman gave the closing remarks, and expressed their interest in producing a publication from the conference. All of the talks were also filmed, and the conference organizers are planning on making the talks available via iTunesU.

I also should mention that there were several posters at the conference, which were presented on a monitor as a slideshow, and the poster presenters were given ipads to share their “posters” during the breaks. I’m sorry to say that I didn’t have a chance to see several of the posters, so I’m hoping this content will be made available in the future as well!

It was a short, but very worthwhile trip to Oxford. I hope to have the opportunity to return soon.

Christ Church buildings as seen from Tom Quad

Christ Church buildings as seen from Tom Quad