Category: Art Conservation
Investigating Invisible Inks with the Alumni Professional Venture Fund
September 16, 2026 Written by By Caroline Roberts, Winterthur/91原创 Program in Art Conservation Class of 2011 | Photos by Caroline Roberts
W91原创PAC alumna Caroline Roberts used support from the Alumni Professional Venture Fund to reveal images and inscriptions visible only under ultraviolet light.
I am an archaeological conservator at the University of Michigan鈥檚 Kelsey Museum of Archaeology鈥攁 job I love and one for which my education in the Winterthur/91原创 Program in Art Conservation (W91原创PAC) prepared me well. At W91原创PAC, I specialized in objects conservation, with a minor in preventive conservation. Immediately after graduating in 2011, I joined the Kelsey as a one-year fellow. My fellowship research project focused on developing a preservation plan for the museum鈥檚 collection of 200 carved and painted limestone stelae鈥攁ncient grave markers鈥攆rom Terenouthis, Egypt. These objects, which date to Egypt鈥檚 Roman period, have remained a central focus of my work ever since.
I applied for an Alumni Professional Venture Fund award to investigate an intriguing type of inked decoration on the stelae that becomes visible only under ultraviolet (UV) light. While examining traces of pigment on the Kelsey鈥檚 funerary stelae, I discovered images and inscriptions on several objects that could be seen only under UV illumination鈥攕omething I had not expected at all.
As a researcher, I knew that stelae in other collections had not been examined using this technique. I wanted to help recover lost information about the identities and beliefs of the people commemorated on these objects. As a conservator, I also wanted to understand why these features were no longer visible to the naked eye and why longwave UV light revealed them.
With support from the fund, I traveled to Lens, outside Paris, and to London. I arranged research appointments at the Louvre鈥檚 conservation center and the British Museum, both of which care for stelae from Terenouthis. Using a modified digital camera, specialized lens filters and two longwave UV lamps that I brought from the Kelsey, I investigated whether we could reveal additional inked details.
To my great excitement, we discovered several previously hidden features on stelae at the Louvre. These included part of a jackal figure, tasseled shrouds and additional details in a banquet scene beneath a reclining figure.
The fund has been invaluable in advancing our collective understanding of this important group of artifacts. Uncovering lost details across museum collections has renewed interest in the stelae and identified features that help connect objects with uncertain excavation histories to the archaeological site of Terenouthis. The findings also suggest that the deterioration of these features cannot be attributed to a single event.
Just as importantly, the project allowed me to connect with colleagues鈥攂oth old and new鈥攁nd discuss the discoveries from art-historical and scientific perspectives. It demonstrated how much we can continue to learn from museum collections using relatively simple, accessible tools.
I am immensely grateful for the support of the Alumni Professional Venture Fund, and I feel energized to continue researching these remarkable artifacts.
See elsewhere on the ARTC site for information on previous Venture Fund projects focused on bringing training, research, and sustainable practices to new audiences.
