Loop-type binder for documents

A loop-type binder comprises tongues (4) attached on its back cover for holding document sheets, and these tongues (4) constantly increase in thickness from their base (6) to their tip (9), thus comprising a deflection resistant tip and an elastic staff at their base. The radius of the joining area (15) from the tongue to the base is by several times smaller on the side facing the back cover than the radius of the joining area (14) on the side that faces the front cover. The stopper (13) that retains the tongue when the binder is open is integrated into the tongue by a slope (12). This tongue design facilitates convenient and gentle handling and storage of documents (FIG. 2).