RECOVERING AND RE-COVERING: Conservation of a fifteenth-century bookbinding

Books are something of an oddity in the context of a museum in that they are not only objects which we want to preserve for their historical significance but also machines which have a mechanical function to carry out every time a reader opens them. No one in his/her right mind would dream of cooking in a medieval pot or wearing a pair of eighteenth-century shoes – i.e. of using either object for its original function – but the medieval and eighteenth-century bindings in a library are expected to work to allow access to the texts they contain. Continued use, combined with the ageing of materials used in the construction of the bindings, eventually leads to boards becoming detached and sewing structures wearing to the point where they can break, so generations of bookbinders have repaired bindings as a large part of their work.
One of the incunabula (that is, books printed before 1500) in the Founder’s Library had been given a new spine in the late nineteenth century in order to reattach the front board. Unfortunately, the poor quality of the leather meant that the repair itself was deteriorating and the front board had become detached again. In addition, the previous repairer had used a large amount of hide glue on the spine of the book which prevented it from flexing. The result of this repair campaign was to give an early printed book a spine which would look much more appropriate on a nineteenth-century book. A large part of the interest of this binding was in what lay hidden beneath the previous repairs. As conservation work progressed, the book started to reveal elements of its making hidden for over a century.

The book as received, showing the original blind-tooled calfskin on the boards.
The book as received, showing the nineteeth-century leather on the spine.
The large amount of hide glue applied to the spine during the previous repair work prevented the book from opening properly. The image shows the maximum opening possible without breaking the spine!
The nineteenth-century paper paste-down on the inside of the front board appeared to be covering a much earlier sheet of parchment, which is just visible at the tail edge.

On close examination at the bench, it soon became apparent that the sewing structure might well be original and that endbands of braided alum-tawed skin, typical of Germanic bindings of this period, may well have survived under the newer leather on the spine. In addition, a narrow line of parchment was just visible, extending beyond the edge of the nineteenth-century paper paste-downs (the sheets of paper pasted to the inner surface of both boards). Depressions in the pastedowns also suggested that the original pattern of the cutting for the foredge corners of the boards (the free corners on the opening edge of the boards) was of the ‘tongue corner’ type rather than the mitred type suggested by the nineteenth-century repair patches. The ‘tidying up’ by the last repairer seemed to be obscuring a great deal of fascinating information.
After discussions with the curators of the collection, we decided that the need for repair provided a good opportunity to examine the structure of the book further and that the nineteenth-century material could be removed, saving annotations on the newer paper endleaves and the labels for future reference. Unfortunately, the nineteenth-century leather on the spine and at the corners of the boards was far too degraded to save and crumbled into powdery flakes during attempts to lift it. However, when the leather and hide glue on the spine had been removed, it was exciting to find that the original sewing structure and the original braided endbands had survived in a surprisingly good state of preservation, so much so that the whole structure could flex in an excellent opening arch as the original binder intended.

The spine cleaned of nineteenth-century leather and hide glue to reveal the intact sewing structure and braided endbands of a well-constructed early printed book.

Further investigation on the insides of both boards revealed that the original parchment board sheets were still in place and, further, that they were made from a recycled manuscript document which appears to have had at least six seals attached to it on parchment tabs in its original form – the slits for the tabs to pass through are clearly visible in the sheet on the back board (see the lower edge of the sheet in the image below).

Slits in the reused parchment on the inside of the back board suggest that the document originally had at least six seals attached with parchment tabs.

With the leaves of the book flexing from the spine-folds once again, it was also easy to see that the centre of each section had been reinforced by the binder with a folded strip of parchment to help prevent the paper leaves from tearing around the sewing holes. The parchment strips are made from manuscript waste too, although it is not yet clear whether they are from the same document as the board sheets.
The approach to repairing the book was to follow binding techniques of the fifteenth century rather than to re-apply inappropriate nineteenth-century methods. The front board was reattached and the attachment of the back board reinforced with linen braids, secured to the original raised bands with helical stitches of linen thread. The ends of the braids were left long so that they could be frayed out and threaded though the boards next to the original sewing supports to form a sturdy attachment. A slotted loose linen spine-liner was also added to prevent the new leather spine from being adhered directly to the backs of the sections and to form new inner joints in the repaired binding. The lining was carefully cut to fit around the endbands, which remain exposed as the original binder intended.

Linen braids and a loose linen spine-liner in place, ready for the reattachment of the front board.

New archival tanned calfskin was toned and pared to blend in with the original leather before being adhered with wheat-starch paste, again leaving the endbands exposed. The book was then put into a finishing press and strong cord was used to hold the leather tight to the spine and raised bands in the traditional manner during drying.

The re-backed book tied up with cord to dry.

The corners of the boards were re-covered with patches of the same leather inserted under the original covering material so that the tongue corners are visible once more. When the new leather was dry, the flanges of the linen spine-liner were adhered to the insides of the boards under the lifted edges of the manuscript waste board sheets, which were in turn pasted back into position.

Following conservation and repair work, this book is in safe condition to be consulted by researchers in the Founder’s Library. The opening is greatly improved and many original features of the binding have been revealed for the first time in over a century, allowing the book to give us many more clues as to its making and provenance.

The book after treatment.
The conserved book has a greatly improved opening.
The original recycled parchment manuscript sheets on the insides of the baords are clearly visible for readers.