More important than the rating, you need something with two strands, like a thin jute rope. Single strand twines work most of the time, but they can unravel and pull apart.
Thanks Dave. I found a roll of Jute twine at Home Depot for something like $5. I will check to see if its 2 strands. I would never have thought of that. Thanks. I do come up with some random stuff llama. Can't deny that.