This thread is a stranded form of GSP which has incredible strength for its size. Advertised as "almost unbreakable", it allows tying techniques never before possible while minimizing thread build-up on small flies. It is loosely twisted so, unlike other GSP threads, can be split for dubbing loops if desired, although it is fine enough to be doubled for loops without excessive build-up. The white thread takes marker colors easily. This 50 denier thread has a breaking strength of 67 oz. (1.90 kg). 50 meters per spool.
Because GSP fibers are quite tough, they can damage the blade edge on fine scissors and stainless bobbins. The makers recommend using a ceramic bobbin and cutting with a razor blade. Nano Silk will take most dubbing waxes and this helps the thread stay in place as well as serve as a great dubbing thread. Although it is tough enough to make durable flies without a coating of head cement, UV cure and water-based cements can be used for appearance or texture. Solvent-based glues and coatings are not recommended as they might impair the fibers' strength.