A knot of knot work.
Also known as Macrame lace, it is a knot technic in which a limited number of knots are used, mostly in a repetitive patern, to form flat as well as three dimensional items, often with an open structure. Knots used include Square knotting, double half hitches (also known as clove hitches if used in a different way) and other combinations of half hitches. Macrame has been in fashion in different period, well known era's are the 19th century and the 1970's, for more information see Wikipedia.