Stationers' Liber A
'Liber A' is one of the key manuscripts produced by the Worshipful Company of Stationers & Newspapermakers. Dating from the 16th century when all new publications (plays and books) had to be registered with the city of London livery company, an arrangement that prefigured the legal deposit arrangements of today, Liber A contains essential history of the early publishing industry. Saved by an assiduous clerk at the time of the Great Fire, when many other records were lost having been placed for safekeeping in St Pauls around the corner, it lasted into the 20th century remarkably well, albeit having suffered from damp and mould.
In 1965 the well known bookbinder Sydney ('Sandy') Cockerell repaired and rebound the manuscript. A label on the back board endpaper outlines treatment including the use of barium hydroxide (usually a non-water-based deacidifying chemical), soluble nylon (usually used temporarily to 'fix' otherwise water-soluble inks during a wet treatment and subsequently removed, but often mis-used and left on after treatment) and a tissue to strengthen the weak areas and paper infills. It is not clear if he did actually use nylon, and he may have removed it, nor why if he intended not to use a water-based treatment, but it is clear he used a heat-set (iron-on) adhesive-coated tissue of the time to support Bodleian paper infills, possibly a product known as 'Crompton tissue'. This tissue has not been sold since the 1990s, following increasing evidence of discoloration over time. The pictures in the Gallery to the right show the lines of pressure from the iron used to apply the tissue and the, sadly indelible, grey discolouration of the adhesive extending beyond the brown mould staining.
Roll forward 50 years and it became apparent that the pages were sticking together. The problem was getting worse with every manual separation of the pages reverting to a solid block of stuck sheets soon after, making access impossible and each separation increasingly risky. Whether the heat-set tissue was the culprit or his exmperimental cocktail of chemicals, it is not clear, but the time had come to address the problem.
NCS was called upon to treat the manuscript and save it from its sticky end. Tests showed that alcohol would remove the blocking tissue and residues of adhesive. Each page, both sides, had to be treated individually to remove the tissue and adhesive, left to allow the alcohol to evaporate and then new tissue applied to support the paper infills and weak edges. Before carrying out the work the volume was digitised so that access could be widened and regular handling reduced. A very lightweight (5gsm) long fibre Japanese 'tengujo' tissue was used, providing strength but with a good level of transparency where edges of text might be covered. To avoid moisture affecting the mould staining and inks, a cellulose paste was used ('Klucel G'), mixed with alcohol. Cellulose ethers such as this have not been observed to break down and become tacky over time, principally because they do not contain an additional plasticiser that is used to activate adhesion, as with Crompton and similar early heat-set tissues.
Now Liber A can be opened safely again. We hope to have laid to rest this ghost from the days when chemical science was thought by bookbinding repairers to solve all problems, with luck no longer to haunt the City of London. If anyone readng this has come across similar problems we would be interested to hear, write to us at firstname.lastname@example.org