Image Description: In this image we see the structures inside the spine of a medieval book. The book is a French Book of Hours produced around the year 1500, which is owned by Western University, London, Ontario. We can see the cord sewing supports from the current eighteenth-century binding, on to which the groups of pages are stitched. But, between the sewing supports are four double lines of holes in the backs of the pages. These holes are the empty spaces where a previous set of stitches attached the pages to a previous set of sewing supports. From them, we can tell that this book used to be bound on four split leather supports (instead of three cord ones). We have been calling this evidence of previous binding structures a “ghost binding”. It is important because very few medieval binding structures survive to the present. So, this image is part of a project to provide (non-destructive) insight into the range of binding techniques used in different parts of the world. The information found contributes to a global story about transmission and exchange in the development of books. It will help scholars and conservators working with these fragile medieval materials make decisions about their preservation. 

Why did you conduct this research? MicroCT has not previously been applied to the study of bookbinding. This scan is a proof-of-concept study for a larger project that uses this method to compare the materials and craft techniques used in premodern written artefacts from around the world, overturning Western-centric histories of text technologies by highlighting the global networks exchange that underpinned the development of the modern book. We began with this book because the binding type is well-documented and we were confident we could identify any structures revealed by the scan, but as this image shows it still had the capacity to surprise us!

Technique: This image was produced using micro-computed x-ray tomography. In microCT imaging x-rays are fired from a radioactive source towards a sensor, the book sits between the source and the sensor. By rotating the book we can take many images from different angles. These are built up to produce a 3D representation. This scan has a resolution of 80µm, meaning each pixel represents an area with a diameter roughly the width of a human hair. This image is a single slice from our scan. A colored filter has been used to enhance the clarity by highlighting different densities of material. 

Acknowledgements: Funding body: The Leverhulme Trust; collaborators: Andrew Nelson, Western University (scanned book); Deborah Meert-Williston, Western University (librarian); Alexandra Gillespie, University of Toronto Mississauga (PI); Jessica Lockhart, Old Books New Science Lab, University of Toronto (Head of Research).