More information on Single Braids:
Dyneema and vectran single braids are great for halyards, tack lines, high load applications and lightweight stainless steel wire replacement. These synthetic ropes have minimal stretch and superior strength.
The fibers of high tech single braids are smooth and slippery providing minimal chafe and abrasion. Due to their high strength and low stretch properties, they have nearly infinite uses from halyards, sheets, backstays, travelers, vangs, and more. Some boats are even using them for standing rigging or convertible cutter/solent stays.
Dyneema, also known as Spectra or Ultra High Molecular Weight Polyethylene (UHMWPE), is an extremely lightweight, strong, low stretch and durable rope. It is also UV stable, especially when treated with a line coating. Vectran, a type of liquid crystal polymer (LCP), is very similar to Dyneema with a few key differences. Vectran has stretch, or elongation under load, comparable to Dyneema but much less creep, elongation over time. Vectran also offers a higher resistance to heat. The trade off comes in that it is not as UV stable as Dyneema, and depends more on a coating or cover for sun protection. When winching or cleating either material, a cover is usually preferred to provide grip and bulk.
Check out the APS blog for a more indepth look: