Details Mylar cord is a versatile and popular fly tying material known for its reflective properties and durability. It&';s made from thin strips of Mylar, a type of polyester film, which is coated with a reflective metallic or holographic finish. Whether used as a body material, ribbing, wing case, or flash accent, Mylar cord can enhance the effectiveness of a wide range of fly patterns for both freshwater and saltwater fishing.