Abstract: The invention is a filament tensioning device for use on a spool of a type having filament coiled around a cylindrical barrel bounded by flanges at each end of the barrel. The device, constructed in accordance with the present invention, includes a belt or strip of elastic material such as neoprene. The elastic strip is formed into a ring and end portions adjacent the long ends of the strip are bent transverse to the outer surface of the ring forming a radially extending tab. The two end portions are attached and preferably stitched together using two seams, thereby forming a passage therebetween which extends from the strip ends through the length of the tab into the interior of the ring.In use, the filament tensioning device is placed over the barrel of the spool between the flanges and elastically contracts about and circumscribes the coiled filament.