The sheet bend (also known as becket bend, weaver's knot and weaver's hitch) is a type of knot, related in structure to the bowline. It is very fast to tie and is useful when joining two ropes of different diameters or a rope to a sheet corner. Along with the bowline and the clove hitch, is often considered one of the most essential knots. It is a more secure replacement for the reef knot (square knot), especially in its doubled variety.
To tie the sheet bend, take the larger rope (or sheet) in one hand. Make a loop in this rope about three inches long and hold both ends of the loop in one hand. Next, take the smaller rope and thread it up the loop. Then wrap the smaller rope around the loop of the larger one going first round the short end. Then tuck it underneath where the smaller rope comes up through the larger rope's loop. Finally, pull the free end of the smaller rope tight to secure the knot.
Make sure the two free ends are on the same side of the knot; otherwise you get a left-handed sheet bend—a knot of significantly reduced strength.
One type of weaver's knot is a sheet bend, tied with a different approach.
If the two ropes to be tied are of very different diameters, the double sheet bend holds better. The only difference is that the smaller rope wraps the larger rope twice.
The double sheet bend or double becket bend is a doubled version of the sheet bend. It is more secure than the simple sheet bend, especially when the two lines tied together are particularly different in thicknesses or rigidity.
To tie the double sheet bend, tie a sheet bend, then again pass the working end along the same path, around behind the bight and beneath the loop in the smaller line. It is the smaller line that is wrapped twice around the other.
As with the standard sheet bend, the two free ends should end up on the same side of the knot. Note that in the picture to the right, it is unclear that the upper end of the larger-diameter rope is the free end.