Diagram 4: Curved shape of a book spine

      In early bindings and in some hand bindings today, the boards are laced onto the book block and then covered with leather or fabric. In most bindings today, the cover boards and cloth or leather are put together first then adhered to the book block. This is called case binding.

      In a paperback book, the folded edges of the spine are usually not sewn but are ground away, adhesive is applied, and the soft cover is glued on. The glue used for older paperbacks is prone to drying out, leading to loose pages.

       Preservation Concerns

      Books are sensitive to all the environmental factors already considered: light, temperature,relative humidity, and infestation (mould, insects, or rodents). One important factor in the deterioration of leather bindings is air pollution. The absorption of chemical air pollutants, especially sulphur dioxide from car exhaust, accelerates the breakdown of the natural oils and fats in leather, causing bindings to crack with normal handling. There are many abrasive particles present in the air; these particles land on the books causing deterioration of the exposed edges of the paper and bindings, staining, and abrasion.

      It is easy to damage a bound volume through poor handling. Removing a book from the shelf by pulling at the top of the spine (head cap) results in damage and tearing of the binding. Books with damaged spines or failing bindings need adequate support when being handled to prevent separation of the book block from the binding. Additional handling recommendations can be found in Appendix 4: General Rules for Handling and Moving Artifacts and Works of Art.

      The information in books may need to be shared among several people, but photocopying a book is discouraged. Most photocopiers require that a book be open to lay flat at 180 degrees. This can fracture the spine of the book, crack older or desiccated (dried out) adhesives, and break the stitching of older bindings, causing pages to loosen or fall out. If you have to make photocopies, it is important to make one copy onto a permanent durable paper using an electrostatic copier with edge platens that allow books to be copied at 90 instead of 180 degrees. Additional copies can be made from this high quality master.

       Preventative Conservation of Books

      The first step is always to thoroughly examine your book to check for damage, potential problems, and the overall structural stability of the work. One of the most helpful things that can be done at home is good housekeeping. Thoroughly dust the books and storage area and inspect for mould and insect infestation at least once every 12 months.

      Surface dirt should be removed not only to improve the aesthetics of the book but also to eliminate a hazard. Dirt is abrasive, it may be acidic, and it holds moisture that promotes the growth of mould spores. A very light, dry surface cleaning will reduce the amount of dust, fibres, and other foreign materials that may have collected on the surface of the books.