Hemingway’s Ultra Strong GSP thread is one of the strongest threads available. GSP stands for Gel Spun Polyethylene, a material known to be stronger for its weight than steel. The thread was made by spinning continuous ultra-strong fibers of GSP. This GSP thread is supple and lays flat when tying, it is UV resistant, and will not absorb water. It is a 100 Denier, all-purpose, and super-versatile thread - it works great for most fresh and saltwater fly sizes and patterns. Simply irreplaceable when tying deer hair flies. Each spool comes with 50 yards (about 46 m) of thread. This is a 100-Denier thread and is available in Black and White.
