As we stressed in our previous post, the binding and mounting system adopted in the late 19th or early 20th century to accommodate the folio fragments of Codex Usserianus Primus (TCD MS 55) proved unsuitable over time. The main problem was that the card in which the fragments had been pasted resisted the natural curling movement of the vellum, causing strain on the already fragile leaves.
The binding was thus removed and it was decided that each fragment should be released from its buckling card mount in order to be re-mounted in a manner which would improve its preservation. The following method was adopted.
The first stage involved the careful release of the folios from their card frames, followed by removal of any adhesive residue. The challenge was to design a system to securely house each fragile vellum fragment using the minimum of materials in direct contact with the badly gelatinised edges. Our solution was to attach a number of ‘vellum fingers’ at strategic points, avoiding text and supporting tears or splits (fig. 1). In this short video, you will see this process being carried out on folio 25:
The fingers are only glued at their tips on each side of the folio fragment. The other end of the fingers are attached, again only at the extremity, to a broadly profiled card.
The span of the fingers allows for expansion and contraction in the vellum of the manuscript folio, and reduces the risk of distortion. Once all the fingers are attached (typically eighteen will be used per folio fragment) to the profiled card (fig. 3), it is inserted into an outer fold of card with a closer profile shape cut out from the centre (fig. 4).
The format of the card is based on an estimation of the original size of the folios. The outer and inner cards are adhered to each other with dabs of adhesive, resulting in a rigid support for the folio fragment. Finally, each mounted folio fragment is housed in a purpose made folder and boxed.
John Gillis, Preservation & Conservation