Tag Archives: Infrared

Archeological Textile Discovery in the Stacks: The Research

This is the first post of a four part series.

Discovery in the Stacks

When a collection of Egyptian mummy bandage fragments at the Cincinnati and Hamilton County Public Library was found in an area used to store uncatalogued flat materials, the lab was asked to play a role in providing better stewardship.  

Discovered in the stacks: A mounted collection of six Egyptian textile fragments that date to the Ptolemaic Period (around 300-30 BCE), recto

Mummy bandage wrappings are rare finds in public libraries, and discovering that the materials where uncatalogued was not terribly surprising; having the specialized knowledge to catalog such a unique object may not have been available at the Public Library at the time of the acquisition.  With no identifying marks, and mounted to an aged board, the provenance of these objects are unfortunately unknown.

Collection suffered from a lack of storage housing without identifying information, found by staff performing a collections inventory, verso

Concerned about their overall safety of the fragments, as they were attached to a brittle board that could potentially chip and break if mishandled, it was clear that a solution for long-storage was needed.  Therefore, the items were brought to the lab for a comprehensive examination.

As a book and paper conservator with little knowledge of archeological textiles, the first step towards selecting a preservation solution was to better understand the fragments and conduct research on how to care for them. Because of the age and fragility of the items, my goal became to find a storage solution that could facilitate access while limiting handling of the actual objects themselves.

Examination

In order to conduct research, the condition of the individual fragments were fully examined with a variety of illumination techniques to better understand their composition. The collection was photographed with a DSLR camera in normal illumination, raking light, infrared, and ultraviolet fluorescence. The images revealed valuable information such as the possible types of adhesives used in mounting, the degree of linen loss, as well as the type of pigment applied to the linen. 

Creating the photographic documentation also allowed me to reach out to other scholars, to inquire about their history, while providing high quality images.

Types of Photography Performed During Examination

  • Normal Illumination – Overall images were taken of both the front and back of the mounting board. Normal illumination images serve as general reference photographs, representing how we perceive the object in normal room lighting.
  • Raking Illumination – Reveals the surface topography, showing breaks, tears, and losses in both the linen fragments and the mounting board.
  • Infrared Imaging – A modified DSLR camera and specialized filters remove visible light and capture longer wavelengths than the human eye can see, revealing the carbon-based writing while allowing the stains to disappear, making the writing more legible.
  • Ultraviolet RadiationUltraviolet radiation produces a fluorescence that readily shows the two differing types of adhesives used to adhere the fragments onto the backings. The first adhesive used to adhere the fragments to a brown paper backing does not fluoresce, while an adhesive that is smeared onto the face of the backing board does fluoresce.  This indicates that the fragments were adhered at different times to the two different substrates, first being adhered overall to a paper backing, then later mounted onto the board.

Research

Using the high-quality images described above, I reached out to experts in Egyptology and papyrology at the University of Cincinnati Classics Library and the University of Michigan to learn about the history of the objects. Right away, I was given extremely detailed information by generous colleagues.

One of the first surprising things I learned is that two of the fragments were oriented upside down.  So in their mounted format, they were not properly represented. Perhaps even more exciting was the discovery that three fragments were able to be attributed to a priest named Wennofer! (There will be more about the history of the pieces in the second part of the series, stay tuned.)

Of Parts and Pieces

It was serendipitous that during my research one of the contacts I was put in touch with was Dr. Ann-Katrin Gill from the University of Leipzig.  Dr. Gill happened to be in the midst of a larger project titled: Of parts and pieces: unearthing, reassembling, and documenting papyri and linen objects in US libraries.  As you can imagine, she was thrilled to receive the treatment documentation of the Public Library’s fragments to add to the collection.  We have hopes that should any other fragments belonging to these be discovered, perhaps they could become reunited.

Materiality

The Egyptian mummy bandage fragments, or cloth shrouds, are also referred to as archaeological linen textile fragments. I learned the following about the materiality of the fragments.

Inscriptions

Fragments contain either formal hieroglyphs (using pictorial characters) or cursive hieratic script (which is a later Egyptian shorthand writing system used by scribes). It was determined that the fragments likely date to the Ptolemaic Period (around 300-30 BCE) based on the writing style used during that time period. 

Inscriptions are written in black ink with a reed or rush pen, referred to as rush ink.  The ink appears to be typical of the time period, most likely carbon-based with a gum binder. The fragments when viewed though infrared imaging (see slide show above) shows the carbon in the ink absorbing infrared radiation, making the ink appear dark black in infrared images, while the organic staining drops out of the image .

20th Century Alterations

Lined with Brown Paper

At some point in the fragments’ history, the textiles were lined on the back in an acidic machine-made brown paper (reminiscent of brown craft paper tape).  If you look carefully in the raking light image (see slide show above), you might notice the brown lining paper poking through losses in the textiles as a slightly darker shade of brown than the board support.  Under UV fluorescence (see slide show above), the adhesive used in conjunction with the brown paper lining does not fluoresce. This adhesive was found to be readily water soluble and possibly a gum-based adhesive.

Trimmed Edges

You might notice the fragments are cut into odd shapes, likely they were trimmed to remove frayed ends and damaged parts.  There’s no way to know if the fragments were trimmed before or after they were lined with the brown paper lining, however the edges are fairly consistent with one another. One could make the case they were trimmed at the same time.

Mounted to a Board

After lining, these fragments would have then been mounted to a board, with two identified as upside down (oops)! Faint patterns on the back of the paper board resemble off-setting from wood, likely caused by a wooden backing board in a frame. If these assumptions are correct, it’s my guess that the fragments were mounted then framed for the tourist trade, with the frame now lost. 

Condition

Being mounted on an aged, unsupported, brittle board put the fragments at risk of breaking along with the board. Since the board already contained cracks and breaks along the edges, this concern felt urgent.

Despite the precarious storage and concerns surrounding the fragments being exposed to the elements, the textiles themselves appeared in fairly good condition for being over 2,000 years old! Viewing the fragments in raking light (see slide show above) reveals a considerable amount of linen loss throughout the textiles. However, it doesn’t appear that these losses were a recent incident in the past half century.  The losses were likely present when the fragments were lined with brown paper backing.

Next Steps

Next steps were to prepare the objects for safe keeping in long-term storage. To do so, required research on possible treatment options to safely store the items in their proper orientations. Also, knowing that not all fragments belonged in context with each other was further justification to split the collection into separate parts. Read on for more discoveries in this preservation journey!

To learn more, check out the other three posts in the series. (Links will be made live as the installments are released.):

  • History – Historical information provided about the Egyptian inscriptions
  • Treatment – How the materials were treated after learning about their content
  • Storage Solutions – Individual solutions for separated fragments as well as storage as a collection

Acknowledgements

  • Katherine Davis, Lecturer in Egyptology in the Department of Middle East Studies at the University of Michigan
  • Suzanne Davis, the Associate Curator and Head of Conservation at the Kelsey Museum of Archaeology at the University of Michigan
  • Dr. Ann-Katril Gill at the University of Leipzig
  • Marieka Kaye, Harry A. and Margaret D. Towsley Foundation, Head, Conservation & Book Repair, University of Michigan Library
  • Obie Linn, Textile Conservator at the Cincinnati Art Museum
  • Ann Wuertemberger, Catalog Librarian at the Cincinnati and Hamilton County Public Library
  • Meredith Montague, Textile Conservator at the Museum of Fine Arts Boston

Ashleigh Ferguson Schieszer – Special Collections Conservator and Co-Lab Manager [CHPL]

Fun with PhotoDoc: Infrared Again (Edition 8)

It’s been a while since my last Fun with PhotoDoc post, so I wanted to share some progress I’ve been making with Reflected IR.  You might remember from my last PhotoDoc post, we purchased a modified UV-Vis-IR camera from MaxMax at the end of 2017.  Our first two objects we (Ashleigh and I) examined and documented with the camera were a great learning experience, but didn’t exactly leave me with goosebumps.  Still it was a good experience and we worked out the use of the various filters and the general IR workflow.
Fast forward to April when the lab received not one but two books from UC in need of IR photography.  The first was the Masters thesis of Ralph E Oesper from the Oesper History of Chemistry collection.  The curator wished to exhibit several of the pages from the volume, but upon inspection Ashleigh (our conservator) was concerned that the purple text ink might be dye based, which is very light sensitive.

The ink disappearing under near IR is a clear indicator that the ink is most likely dye based, and while that made Ashleigh very happy and validated her choice to create printed surrogates of the pages for exhibition, I still felt a little less than wow’d.  I was still waiting for a really compelling and dramatic IR example.
Enter volume 1 from the Third German Protestant Church of Cincinnati collection, an 18 volume collection of early Cincinnati baptismal, marriage, and funeral records from the Archives and Rare Books Library that pre-dates the city records.  In this case, Ashleigh wanted me to examine and document 4 pages within the volume with faint graphite inscriptions on paper with heavy foxing.

Side by side comparison of one page under normal illumination and near infrared

Finally!  A satisfying IR session with helpful results.  Documenting all four pages using reflected IR allows for the foxing to disappear from the page, thus making the faint graphite inscription easier to read.  After converting the IR image to grayscale I also upped the contrast significantly, allowing for better readability of the handwriting.  In the end, we now have four pages of legible inscriptions and I’m very happy with the results.

Click on an individual image to see the gif in action for that page…

I definitely still have a lot to learn when it comes to near infrared photography, but I would call this, not only a satisfying experience, but progress that will hopefully lead to a better workflow.  This round of IR photography definitely was not seamless, but I did learn more, as I do every time I shoot, and it is my hope that the more I do the more I will streamline and improve our IR workflow.

Jessica Ebert (UCL) – Conservation Technician, Lead Photographic Documentation Tech

Fun with PhotoDoc: Infrared (Edition 7)

At the end of last year the lab purchased a modified UV-Vis-IR Nikon through MaxMax so that we can start to play around with infrared photography.  Infrared photography (IR) is commonly used in fine art conservation as an examination tool.  Reflected IR can be helpful when trying to identify pigments, inks, coatings, etc. and transmitted IR can helpful for viewing watermarks, underdrawings, and linings. We’ve only just started dabbling with IR photography, but I wanted to share some photos from my most recent session with reflected IR.

This is a full leather photo album from the Public Library of Cincinnati & Hamilton County’s collection.  This early 1900s photo album contains hand-colored silver gelatin photographs taken by A. Nielen.   The photographs appear to depict his travels through the US and Canada, and various landmarks and neighborhoods of Cincinnati are represented.

This seemed like a good object for reflected IR because of the hand-coloring on the photographs and the white ink inscription below each photograph.  I began by taking a representative visible light image (first image below) using our modified UV-Vis-IR camera, incandescent lighting, and the X-Nite CC1 filter on our 50mm lens.  Then, being careful not to move the position of the camera or the object, I switched to the X-Nite 830 filter (830nm) and converted that image to grayscale in Photoshop (second image below).  Then I took my visible light image and my reflected IR image into Photoshop to create the false-color image (third image below).  The digital false-color image is a combined representation of the visible and infrared images, and it’s actually quite simple to make.  You basically copy and paste the various channels for the VIS and IR image as follows, green to blue, red to green, and IR to red.  The false-color image allows you to better differentiate and characterize the various materials (pigments, inks, etc.) and potentially even identify them if you have sufficient known samples to use as references.

Like I said, we’ve only just started using IR and we’ve got a long way to go, but I’m looking forward to experimenting and learning more about it as time goes on.

Jessica Ebert (UCL) – Conservation Technician & Photographic Documentation Tech