Byzan… er… medieval Eastern Roman coins. Photo Scott Coleman.

As discussed in my previous Xlab post, I am interested in applying Reflectance Transformation Imaging (RTI) and photogrammetry/3D imaging to study Byzantine (Eastern Roman Empire) coins. In particular, I want to explore how these methods can be implemented to create better accessibility for scholarly and public engagement with Byzantine coins. My initial intentions for applying RTI have led me down another path for its application beyond generating high-resolution digital accessibility. Along with Xlab, I participate in the Inhabiting Byzantine Athens Project (IBAP), headed by Dr. Fotini Kondyli from the University of Virginia. For this project, I am reassessing the numismatic legacy data from the 1930s Athenian Agora excavations, including analysis of wear and clipping patterns of middle-Byzantine (1100 – 1250 CE) coins while creating a more extensive digital coin database. So why am I telling you all of this?

My inquiry for the IBAP aims to understand coin circulation during the Byzantine rule of Athens to the Frankish occupation and if the Franks chose particular coins (i.e. Manual I Komnenos) to keep in circulation and why. RTI can help us with our research questions by providing data on use-wear and clipping patterns which is critical for understanding how long Byzantine coins remained in circulation. However, concerning clipped coins, we first need to establish whether the coins were clipped during the Byzantine rule of Athens or after. If the coins were unclipped before the Franks recirculated them, then why would they clip them?  What can this tell us about the value and reuse of Byzantine coins to the Franks of Athens? Circling back to my Ph.D. research, if RTI can help demonstrate that Byzantine coins were reused and recirculated in Athens with many diverse groups of people using them, how does this affect their representation in museums? RTI may provide some insight into the former questions, but it certainly problematizes the latter. But this is a good thing, right?

Moving forward, I recently read Coules et al. (2019) and Newman (2014), who have both explored RTI’s applications for wear-use analysis in engineering material failure and bone tool surface modifications, respectively. Next on my reading list is Min et al. (2021), who have explored RTI’s applications for documenting coin conservation processes, which I intend to apply to detecting coin damage caused by conservation processes versus day-to-day wear and abrasion. Based on the two former articles, RTI has the potential for analyzing wear-use and clipping patterns; however, the former may be slightly more problematic than the latter. This is because RTI is an excellent tool for identifying striation patterns, imperfections and modifications that are difficult for the human eye to detect. Unfortunately, RTI is not as precise for measuring height and depth, which is needed for wear-use analysis. Coules et al. and Newman demonstrate RTI’s limited magnification capacity, which creates problems for accurately analyzing material fabric height and wear (Coules et al. 2019: 1013-1014; Newman 2014: 544). Nevertheless, the potential for the RTI software to provide new insights for coin circulation based on use-wear and clipping patterns is exciting, and it may prove fruitful when applied alongside 3D imaging. Also, such analysis may provide new interpretive and interactive mediums for public engagement with coins, which can inform and remove overly-simplistic narratives that tend to be attached to Byzantine coins…I mean medieval Eastern Roman coins.


Coules, H.E., P.J. Orrock, and C.E. Seow. 2019. Reflectance Transformation Imaging as a Tool for Engineering Failure Analysis. Engineering Failure Analysis (105): 1006–1017.

Min, Jihyun, Sanghoon Jeong, Kangwoo Park, Yeonghwan Choi, Daewon Lee, Jaehong Ahn, Donghwan Har, and Sangdoo Ahn. 2021. Reflectance Transformation Imaging for Documenting Changes through Treatment of Joseon Dynasty Coins’. Heritage Science 9 (1): 105.

Newman, Sarah E. 2015. Applications of Reflectance Transformation Imaging (RTI) to the Study of Bone Surface Modifications. Journal of Archaeological Science (53):  536–549.