Black bungee cord, can be stitched or knotted into place to tension sails and spars. Sold by the yard.
Bungee (shock) cord — Fly Market Kitemaking Supply
48 Rubber Shock Cord 1/4 wide. [45104]. Rocketarium : Rocketarium Model Rocket Kits, parts and launch supplies
Installing Hog Rings on Shock Cord
Bungee Cord Buy Bungee Cords with Strong Bungee Cord Elastic - Atwood Rope – Atwood Rope MFG
Shock Cord (1/2 x 150') - Roll Tarp Products & Accessories
Everything you need to know about bungee cord - Ropes Direct Ropes Direct
Shock Cord, Elastic Rope, Bungee Cord Rope
Bungee Cord - High Strength 3/6, 1/4, 5/16, 3/8 Shock Cord
Ultralight Shock Cord Lashing Lightest Backpacking and Hiking Cord – Zpacks
Rupp Shock Cord Assemblies are the ultimate rigging component. Durable 1/4” shock cord secures a stainless steel snap swivel and a single or double Rupp pulley. Also available with stainless steel snap swivel at both ends (multi-purpose).
Rupp Single Pulley Shock Cord Assembly - CA-0118