1. A method of printing at least one indicia on at least one edge of a plurality of leaves assembled one on top of the other to form a book or pamphlet, the at least one indicia being formed by an assemblage of pigmented marks on the assembled plurality of leaves, the method comprising the steps of: (a) decomposing the at least one indicia to be printed by computer into a matrix of pixel elements; (b) assigning by computer x-y coordinates to pixel elements such that each y-coordinate is assigned to correspond perfectly to the pagination of each leaf of the plurality of leaves, and each x-coordinate is assigned to correspond to a pigmented mark of the assemblage of pigmented marks; and (c) prior to assembling the plurality of leaves to form a book or pamphlet, printing the assemblage of pigmented marks on the at least one edge of the plurality of leaves at the assigned x-y coordinates.