What are Library Oversewn Hardbound Books?

Sections of the book are placed into the machine at a 45 degree angle and are then clamped. Vertical punches (spaced 1 inch apart) punch holes through the pages of each section. Threaded needles pass through the punched holes, enter through the spine, and exit the section approximately 3/16 inch in from the back edge of the page. Horizontal shuttle needles then pass through each of the separately formed thread loops and complete the stitch. The process is repeated to form successive lock stitches up the spine of the book.   When all pages have been stitched, the raw book is then glued and reinforced with woven fabric.

This section is drawn from information online at http://gregathcompany.com/index.html & http://gregathcompany.com/hb/index.html