Dacron is a trade name held by DuPont for its polyester materials and it is made specifically for sailcloth. Dacron is DuPont's Type 52 high modulus fiber; brand names of similar fibers include Terylene, Tetoron, Trevira and Diolen.
The material is popular for sailcloth because it has a low absorbency, meaning that it can dry quickly. It is also resilient and resistant to abrasions and ultraviolet light damage. It can flex without damage and is also cheap to make and to purchase. It is a popular sailcloth material; however, for racing, there are more advanced fabrics used to make sails.