Most cruising sails are made with a laminate that has taffeta on one side and exposed Mylar on the other. The tapes for Tape-Drive or X-Drive sails are bonded to the mylar side. For extra abrasion resistance and protection of the tapes, taffeta can be applied over the tapes, totally covering the second side of the sail. The taffeta layers also make the sail look like it is made from a woven material instead of a laminate.
Titanium sails can be made with taffeta on both sides of the finished laminate. As shown below, this makes the highest performance cruising sail UK Sailmakers makes.
Taffetas come in white and grey.