Conservation of a Green Parchment Ledger Book
By Lucy Cokes
By Lucy Cokes
The Vandewall family owned copperas factories in East Greenwich. Copperas (ferrous sulphate) is made from the oxidation of iron pyrites and is used as black dye for woollen cloth and in inks. The account book, starting in 1761, belonged to Martha Vandewall. Samual Vandewall left his vast fortune after his death to Martha and to her children from her first marriage to Harris Neate. The current owner of the book is a descendant of Neate; the Ledger serves as a historic record that provides many interesting stories, for example, the artist Joshua Reynolds painted portraits of the children and there is reference to this within.
The book itself was bound in green parchment and its parchment sewing supports were laced through the boards. Parchment is subject to warping and movement, and, when used in a binding, this can have disastrous consequences on the book's condition. The parchment was torn, with losses (missing sections) in places. It had become brittle as it aged and had split in the joint (see Image 3). The book had suffered from water damage: some pages showed mould discolouration and the paper had softened. The boards had become delaminated, were soft and pliable and were considerably warped. The book had previously been repaired with tape.
It was decided that the book would be repaired within the principles of minimum intervention - that is, stabilising the object with as little treatment as possible. First, the entire text block was surface cleaned with a smoke sponge and brush, taking care around the areas of softened, damaged papers. As there were signs of mould damage, the book was cleaned with local extraction to remove any harmful debris as a precaution.
Cleaning nearly every page had the added benefit of informing the conservator of any issues within the text block, such as several minor tears and the first and last sections of the book being split (see Image 6). As the book was written in iron gall ink, it was important that any repairs involved as little moisture as possible - components of the iron gall ink can be soluble when exposed to water, and there is a risk that harmful iron ions can spread from the ink to other areas, causing damage to the paper.
To this end, remoistenable tissue - Japanese tissue paper coated with hydroxypropyl cellulose (Klucel G) - could be used. This works by reactivating the Klucel G (the adhesive in this repair) it with very little moisture from a dampened sponge and placing the tissue over the tear area, with very little moisture involved. The split sections were reinforced from the inside with an inner Japanese paper hinge. Parchment losses on the board and covering material were infilled with toned Japanese paper.
The water damaged and softened corners of the text block were likely to fall apart when handled. Water damage had caused loss of sizing in the paper. Traditionally, sizing is used in paper making to make a better surface on the paper for taking writing inks, also providing some strength to the paper. The sizing, however, had been washed away by water. It was resized with Klucel G in isopropanol, consolidating the surface. Due to this, the corners are no longer soft or 'mushed' together and can be handled in relative safety.
One of the most difficult processes within the treatment was deciding how the spine pieces were going to be consolidated. As parchment remained on the spine, it would have been too interventive to give the book a new one. Instead, a laminate of cotton fabric and toned Japanese tissue was inserted at the joints under lifted parchment and folded under itself to create a new head-cap.
The laminate was covered with a thin layer of EVA to replicate the shine of the original parchment and the remaining parchment spine was adhered to the laminate with gelatine. This has worked quite well and now the binding is able to be opened safely.
The warped and delaminated boards also proved to be a difficult problem to solve: the boards were made by pasting together sheets of paper, but water damage to the book had unstuck those sheets. The delaminated layers were pasted back together with wheat starch paste.
However, even after drying the boards under weights, they were still warped. Moisture was introduced to the boards with a blotter damp pack, create from alternative layers of wet and dried blotter and pressed so all blotters in the pile contain more or less equal moisture. This was used to flattening them, but, because of the nature of parchment, the boards wanted to warp in the wrong direction. A new solution had to be thought of, with the aim of warping the boards in the opposite direction to the way they wanted to warp, so that when dry, gravity would make it more or less flat. Therefore, a 'humidification bridge' was made - the board was suspended over two wooden strips and a blotter damp pack with a heavy weight placed over the top was left overnight. This had the desired effect and the board now lies flat.
Finally, a book shoe - a support to hold the text-block of a book and protect the boards from other books - was made to support the book next to its companions on the shelf and the inserted material that was causing discolouration was encapsulated in polyester sleeves.
I have learnt so much from this project and I am really grateful for the opportunities it has given me, from working with iron gall ink to flattening boards and consolidating parchment. The owner was thrilled with the results and the ledger can now be consulted safely.