The trapping mechanism results from a simple conversion of the traction force to an orthogonal component, which enhances the load and thub the friction. type of braid is applicable to sutures in surgery[30], and is also thought to play a role in adhesive proteins(31). Crucial to the geometrical amplification of friction with interleaved books are the angles that the sheets make as they approach the contact region. It is through these angles that the traction forces result in loads perpendicular to the paper-paper interfaces, and thus in large self created friction forces. This fact is easily verified: one can realise an interleaved-book system with 0n 0,