OMCOA Oversewing Machine

***From the Web:

Oversewn bindings are a type of bookbinding produced by sewing together loose leaves of paper to form a text block. Threads pass through small holes that have been punched in the signature's gutter margin(nearest the spine), forming overlock stitches that attach it to previously attached sections. [1] This method of stitching is sometimes called stab sewing. A piece of linen is then glued to the text block spine for further support. The book's spine may be rounded and backed to keep it from caving in, but if the text block is too thick, the spine is sometimes left flat. [2] A strip of cloth called a super is then often affixed to the spine of the text block and then to the boards of the case. Oversewing can be done by hand but is usually done with a machine in a bindery.

Oversewing was frequently used as a rebinding technique for libraries. In this case, the book's spine must be separated from the text block. Usually this requires removing a small section of the leaves' inside margin as well. It is a very strong, durable binding technique.