An engineered polymer thread with a very high tensile strength in relation to its diameter, up to ten times that of steel of the same diameter. This tying thread is suitable for tying flies where a very strong and at the same time thin diameter of the thread is required. A multi-purpose tying thread that covers a wide range of uses, from making smooth and even lower bodies, to mounting coarse skins such as elk and deer, to allowing it to be split for making loops without having to double the wire. Available in black (a solid color that will not lose color during use) and natural white, which may be colored with permanent marker.