The tremendous geometrical amplification of friction through the interleaving of the 2N sheets of each book bears a resemblance to two everyday examples. First, B sailor can moor a large ship simply by wrapping a rope around a cylinder known as a capetan 127, 28). Note that its principle inight be relevant to the interaction between NA and a bacteriophage capsid 129). The second ex- ample is a simple toy known as the Chinese finger trap, where a woven h braid is loosely wrapped around a finger. The braid tightens and the finger is trapped as it is pulled. The trapping mechanism results from a simple conversion of the traction force to an orthogonal com nent, 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 perpen- dicular 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,