Darryl, Burlap or Hessian is correct, with flax/hemp ropes. If you ever get out of the Deep South, Kiwi Disposals (611 Colombo St, Christchurch 365 3381) had some there earlier this year in Green/Brown and also in all Sand. Very reasonably priced at NZ$80 for 16'x12'. If they weren't so big and heavy, I'd have bought a couple!
