In attaching the levers, the outside of the leaf adjacent to the board papers is glued out and the levers are placed approximately 1/8 inch from the spine of the book. The webbings are then glued to the levers and the endpapers are folded over and glued down on themselves, the levers, and the webbings. The clothings are then glued across the spine and onto the folded endpapers. The entire assemblies are then slit at the points of the kettle stitches, the end sections being glued to the insides of the boards and the middle sections between the split boards. The spring-back clamps over the edges of both levers near the spine, and, when the boards of the book are opened, the pull of the levers causes the spring-back to throw the spine of the book up so that the conjugate leaves present a flat surface for writing. To impart added stiffness to the levers, they are cut so that the grain (machine direction) of the board runs at right angles to the spine, which is one of the very few instances in book binding where it is desirable to have the grain in this direction. Also called "stiffeners."
Timestamp: Saturday, 19-Nov-2011 13:18:42 PST
Retrieved: Saturday, 19-Jan-2019 08:42:17 GMT