Workshop ReportSeals and Sealing

1 April 2022

Sealing is a key technique to authenticate written artefacts. But what does the choice of material for a seal depend on? And how can the study of seals benefit from analytical and computational methods? A two-day workshop at CSMC explored a range of questions about the practices of authentication.

The online workshop ‘Seals and Sealing: A Survey of Materials, Forms and Functions’, organised by Philippe Depreux and Claudia Colini, took place from 25-26 November 2021 at CSMC. The workshop had mainly two aims. The first aim was to give an overview of seals and their materiality, allowing comparisons of how documents were authenticated or attested specific qualities in different cultures. The second aim was to show how the application of scientific, analytical, and computational methods can advance the study of seals. Touching upon sealing practices in use in Greco-Roman Egypt, Early Arabic Palestine, Byzantine and Medieval Rus, Medieval Europe, modern and contemporary Nepal, China, and Malaysia, the 11 presentations by 17 researchers provided a comprehensive account of practices of authentication.

The variety of materials, sealing techniques, and functions met with vivid interest and the curiosity of the participants and stimulated lively discussions during throughout the workshop. In particular, three main functions of seals were identified and discussed: 1) authentication/validation, 2) identification, and 3) closing/preservation of the content. It was observed that seals normally served more than one function and that some practices, despite all obvious differences, were common in multiple cultural contexts. These practices regarded, for instance, the symbolic meaning given to specific colours, materials, and the portrayed images, and the significance of physical expressions the body of the sealer in the seal itself, such as the addition of fingerprints and hair. Moreover, the discussions revealed that the selection of sealing materials, in addition to their symbolic meaning, often depended on the materiality of the object to be sealed rather than its function.

Four talks focused on applying analytical and computational methods to the study of seals, showing the synergy of the natural sciences and the humanities. They followed two directions: on one hand, the use of imaging techniques and pattern analysis software tools can enhance the legibility of seals and fasten their classification. This was shown by the contributions presenting Reflection Transformation Imaging (RTI) and the Visual-Pattern Detector tool (VPD). On the other hand, the application of analytical methods can answer research questions connected to the identification of materials and their provenance, for example about the origin of hairs in Merovingian seals and the provenance of Byzantine lead seals.

The workshop is intended to be the first of a series of three. The next workshop, on signatures, has already been scheduled for 3-4 November 2022. The final workshop in 2023 will bring together all the various means of validation in addition to seals and signatures, providing a comprehensive understanding of authentication practices. This series of workshops will result in a multiple-volumes publication.