Solid Braid Nylon Rope in 1/8, 5/32, 3/16, 1/4, 5/16, 3/8, and 1/2 Inch Diameter | eBay
Amazon.com: 328Feet 2mm Satin Rattail Cord Black Nylon Cord Beading String for Chinese Knotting, Macrame, Beading, Necklaces,Jewelry Making Arts and Crafts (Black)