Method for binding a bundle of leaves and a book or folder thereby obtained

A method for binding a bundle (6) of leaves (1), the method comprising the steps of:

• folding each leaf (1) of a plurality of leaves (2), each leaf (1) having an edge (3) and a binding strip (5) located at the edge (3), said folding comprises double folding the binding strip (5) of each leaf (1) over a same line to obtain thereby a first fold line (2) that extends parallel to and at a first distance (A) from the edge (3) of each leaf (1) and a second fold line (4) that is located parallel to and at a second distance (B) from said first fold line (2), the second fold line (4) being located intermediate the first fold line (2) and the edge (3) of each leaf (1), the first and second fold lines extending over an entire length of each leaf (1);
• after said folding step, forming a bundle (6) of leaves (1) with the edge (3) of each leave aligned with respect to one another;
• and
• binding the edge (3) of the bundle (5) of leaves (1),
• wherein each leaf (1) of the plurality of leaves (2) forming the binding of leaves comprises only two fold lines, namely the first fold line and the second fold line, and
• wherein the first fold line is formed and then the second fold line (4) is formed by separate folding over of the leaves (1) along the line forming said first and second fold lines (2, 4).