Books are three dimensional, mechanical structures and as such provide a complex series of problems when these structures deteriorate.
Among the most common areas of damage are the joints and hinges, which bear an enormous amount of stress during opening and closing.
When these fail the boards become loose and can ultimately detach.
Because of their role as a protective case, boards, once detached, render the textblock particularly vulnerable to further physical damage. Bindings are also a decorative feature of a book and the front and back boards are an integral part of this. Information in the form of labels, inscriptions and dates are sometimes found on the pastedown [that part of the board next to the textblock] and their loss too can be highly problematic. Retention and repair are therefore important.
Ideally, the boards would be re-attached by a conservator, but this is a very time-consuming process and as a result many bindings are simply tied together using linen tape. In this way, all the parts are kept together and the detached boards still provide rigidity for the textblock. The sight of linen tape has become a common feature in libraries and is indicative of material highly vulnerable to future loss
some of the tools used
Joint tacketing is a practical process for the re-attachment of detached book boards. It does not pretend to be a full conservation process, but it does allow for the manageable repair of large numbers of bindings.
The other advantage of joint tacketing is its reversibility. It impacts minimally on the look or condition of the original structure.
Not all damaged bindings are suitable for joint tacketing. It does require that the area of repair is robust enough to support a working hinge. If the edges are crumbling or lost then the tackets, or hinges, will pull away the surrounding material causing futher damage and loss.
Through these a thread hinge is tied, the loose ends being feathered out on the inside of the board. It is upon this thread-knot or hinge that the board opens and closes.
The way a joint tacket works is that a very fine hole is drilled in both the spine of the textblock and the corresponding spine of the detached board
...so the new holes follow the existing binding structure
a copper wire loop captures the repair thread...
...captured repair thread
the thread is knotted at the text block spine
the thread tails are then drawn
...from outside the board to its inside
the board is then drawn...
…into alignment with the textblock
the knots are tied off...
...trimmed, feathered and pasted down
References
Robert Espinosa & Pamela Barrios, ‘Joint Tacketing: A Method of Board Reattachment’ in Book and Paper Group Annual, 10 (1991) available on the web
Jane Greenfield, ABC of bookbinding (New Castle DE: Oak Knoll Press, 1998)








