Elizabeth Twining (1805–1889) was a botanist and a botanic artist whose book Illustrations of the Natural Orders of Plants with Groups and Descriptions was printed in London in 1849 in folio. It is thought to rank among the finest lithographic flower books of the mid-nineteenth century.
Senate House Library, the central library of the University of London, holds the quarto edition of 1868. The two-volume set contains 160 colour plates on thick paper bound using caoutchouc, a latex adhesive sometimes known as gutta percha. This adhesive-only binding was pasted into a quarter goat case.
The method of using caoutchouc to glue books was devised by William Hancock, brother to Thomas, the founder of the india-rubber trade in England. William was granted a patent in 1836, to the consternation of bookbinders. The single sheets of the text block and illustrations were held together with layers of a rubber solution from the latex of tropical plants. The spine edge of the book’s leaves were roughened and layers of rubber solution laid down before a final layer of rubber was applied impregnated into a cloth lining. Bernard Middleton in The History of English Craft Bookbinding Technique (1963), and Don Etherington describe the method.
The caoutchouc binding was popular for illustrated “table books” of the 1860s and often used on books printed on very thick paper. It enabled the single leaves of printed plates to open easily. However, over time the caoutchouc became brittle and this, with the stiffness of the thick paper, has seen most caoutchouc glued books fall apart. This has happened to both of these volumes. Every time a reader opened these, no matter how carefully, the pages became detached. Yet the quarter goat case was intact, with only minor damage to the head caps at the joints.
As conservators we aim to preserve the evidence of a book’s history with as little interference as possible, whilst making it accessible to historians and readers. For a book with many loose leaves that cannot be put back together without a great deal of intervention, the best approach would be to box it with its cover and ensure it is handled carefully. This would show the original caoutchouc structure. This book, although beautifully illustrated, is not a first edition, so we decided to look into returning it to its bound state to protect the leaves during use. We wanted to retain the single-leaf binding style but avoid the binding failing again. Bernard Middleton, in The Restoration of Leather Bindings, suggests fanning the spine to apply a sliver of adhesive between each leaf and, if necessary, sawing a groove across the spine into the back of each section to lay a cord in. However, this may need a strong but irreversible glue and we would not cut original leaves. We looked at turning each leaf into a section by pasting the leaves together and sewing the book as a normal binding, but this does not reflect the original style and the thread would make it too thick to be returned to its covers without cutting the leather of the case.
A conservator in America, Susanna Donovan, introduced us to Gary Frost’s unpublished method. He pasted strips of thin Japanese paper to each leaf, extending a feather-cut edge of paper beyond the spine edge.
The feathered edges were then glued to the spine, joining the leaves back into a volume and allowing the book to be returned to its original cover. This retains the single leaves and enables the book to be returned to its binding. Our next step then was to select a strong, reversible adhesive with sufficient flexibility and do a partial mock up.
We found that our most commonly used paste, gluten-free wheat starch, was effective.
The first step was to remove the old caoutchouc glue from each leaf. Alex Bruce, the conservator, found that it came away readily and that the edge was indeed slightly roughened. Care was taken to retain the crease from the original rounding and backing in each leaf.
Narrow Japanese paper guards were pasted onto each leaf, projecting a few millimetres beyond the page. They were cut slightly short of the head and tail so that they did not show on the gilt edge.
The single leaves were gathered together and, surprisingly, there was little increase in swell. Care had to be taken to ensure the leaves lined up with each other, retaining the original text block shape and the curve of the spine. Fine adjustments were made to ensure it would fit exactly into its case and line up with the original squares. Once the text block was in the press, further measurements were taken to ensure it was the correct depth, especially across the joint, and again adjustments were made. The guard extensions were then pasted individually, each one overlapping the earlier one to ensure adhesion across the spine edge of each leaf before rubbing well down on the spine.
Once the text block was re-assembled and dry, Alex put the book into the case to confirm the fit.
The spine was then lined with a thin, strong linen, wider than the spine. The linen extensions were pasted onto the boards under the lifted end leaves to re-attach the text block to the case binding. Finally, strips of paper, toned to match the endleaves, were pasted over the cloth joint. We are confident this adhesive “binding” will last longer than the caoutchouc.
The original caoutchouc-covered textile spine lining was retained and stored with the conserved books.
Alex Bruce trained at the London College of Printing (now The University of the Arts) before working freelance for a number of private collectors and libraries as a book conservator. Alex has worked at Senate House Library since 1998 as a conservator in Special Collections.
Angela Craft studied bookbinding and restoration at Camberwell College in 1980 before working at the National Archives, initially as an archive conservator and later as a book conservator. After a mid-career internship with Chris Clarkson at West Dean College, she studied for an MA in the History of the Book at the University of London. She is currently Senior Conservator at Senate House Library, University of London.