We recommend to use two types of rope construction:
— (1) single braid 12 strand or
— (2) double braid with 12 strand core.
Single braid 12 strand is preferred. It usually is coated against UV and chafe. The best feature about the 12 strand rope construction is that it is really easy to splice. That eases frequent changes of lines. Another advantage of 12 strand line is that can be spliced on used rope, too. If your shroud has crept too much, you just shorten it and make another splice. Double braid rope offers some advantage in chafe protection, but makes the line thicker. It is considerably more difficult to splice. This requires in general that the double braid rope splices are made by professionals.
Please check out the rope manufacturers web sites
— AAmstrand Ropes & Twines
— Gottifredi Maffioli
— Samson Rope
— New England Rope
— Novatec Braids
— Pelican Rope Works
— Marlow — Yale Cordage
and you will find ample info on lines types and materials, or how to make the splices.