This is a quality PVA Cord, which can be used for many uses including tying off PVA bags, for stringers and also to wrap around the hook to stop it being covered in weed. Cord is thicker than PVA String, so easier to use, but not as thick as PVA Tape, it bridges the gap between PVA String, and PVA Tape.
Refills of this are available enabling a further cost reduction.