The property stamp used by the libraries for many books is usually put on the lower right hand corner of the page before the title page.

If for some reason it cannot be applied in this location, then the lower right hand corner of the inside back cover is used. If the paper is glossy (the stamp will then smear) a regular property plate is used instead -- applied to the center of the inside front cover-board.
It is important when using this stamp (or other older-style stamps) not to stress the area where the board meets the spine of the book. In the picture below, the pressure of the stamp stresses the spine of the book at the hinge.When stamping or otherwise putting pressure on the front or back board of the book, be sure the board is lying flat.
NOT like this:

LIKE THIS: notice how the back board is flat. This can also apply to scanning barcodes.
