A though filament for cables.
Crystal Fiber is a material commonly found in cables, ropes, and strings in the gravity age. It is much stronger than duracable; lighter than rope of half the same strength; completely weather proof; behaves like stiff cotton rope; feels like smooth polypropylene.
Perhaps the largest advantage is that it is very difficult to cut. It takes twice as long to cut with a regular knife, but diamond cutting tools cut it in normal time.