Single braids - Used primarily for application where the line is spliced on both ends. Not meant to be cleated unless a cover has been added. Difficult to hold by hand.
Double Braids - Polyester jackets with coated Vectran cores - These lines are used with the cover on or partially removed (stripped and buried). The coating on the 100% Vectran core helps to keep the core weave compact when not under load. Partially stripping the cover removes weight from racing halyards, sheets and controls when minimizing weight is critical. In some lines other materials have been added to the polyester in the jacket like Technora or Cordura to increase abrasion resistance.
Small diameter double braid Vectran lines - These are generally a 100% Vectran core with Polyester (or blended jackets) used in dinghy applications where extremely low stretch and no creep is required and hard wearing jackets can hold up well to abrasion and cleating.