The Constrictor Knot deserves to be much more widely known and used. It is an excellent quick temporary whipping for a fraying rope’s end. It securely ties the neck of a sack or bag, and I have often used it to hold items together for gluing. Its great virtues are that it can be tied quickly and it binds so that it can be almost impossible to untie. It fails is when tied against a flat surface – it requires a curved surface for the binding turn to grip the half hitch.