Double fan adhesive binding, when used with the proper PVA adhesives, is the most durable and flexible binding option for most applications. The Ultrabind machine performs a number of operations. First the spine is milled to ensure that all the old bindings and glue are removed. Next, very small notches are cut into the spine of the book. After this, the spine of the book is fanned twice with adhesive to ensure that all exposed edges are glued. The notches are filled with glue and a reinforcing cloth spine lining is applied to the spine of the book. The book is then allowed to dry. The end result is a very strong and flexible book.
Sewing through the centre folds of periodical issues is the usual choice when the binding margin is insufficient for other binding options. The signatures are sewn securely together and are reinforced with durable linen tape. Centre sewing is not an option for loose leaf or perfect bound magazine issues.
Books that are too thin for the Ultrabind process and have sufficient margin are metal stitched through the side margin of the book. This binding option produces a very strong binding, although flexibility is somewhat restricted.
Retain Original Sewing
Often times, library books require rebinding yet the pages are still held securely together. In this case, the original sewing can be retained. It is usually reinforced with PVA adhesive and durable linen.
Double-Fan by Hand
Volumes sent for rebinding which are too heavy or are too large for the Ultrabind can be double-fan adhesive bound manually using a table mounted clamp. This process involves fanning the spine back and forth while applying the PVA adhesive with a brush. The reinforcing linen is applied to the wet spine and the book is allowed to dry.
Years ago, oversewing was the cornerstone of the library binding industry. Although oversewing produces a very durable binding, the drawback was always flexibility and the loss of a significant amount of margin. Oversewing is still a good choice for papers too stiff or glossy for the PVA adhesives. Due to the advances in PVA adhesives and the Ultrabind technology, oversewing is rarely the most suitable binding method.