Use: A Miller's knot (also Sack knot or Bag knot) is a binding knot used to secure the opening of a sack or bag. Historically, large sacks often contained grains; thus the association of these knots with the miller's trade. Several knots are known interchangeably by these three names. Several variations are shown here.
This is another depiction of the knot shown above.
This knot is also a useful hitch and is known by the name Ground-line hitch when used for that purpose.
This variation is noted as having better binding characteristics than the others.