Chamaenerion angustifolium (fireweed/rosebay willowherb) as a fiber plant

I came across some of last year's fireweed stalks the other day, and felt compelled to peel the bark off a couple of them and make a short length of reverse-wrapped string, just for fun. I've done this before, but don't remember any of it turning out quite this good. Those fibers were strong! When trimming off the little ends of fibers that poked out from the finished string, my nails weren't enough for the job, I had to use my teeth on some of them. The string tolerates quite a bit of tension, even though it's not thick, without showing any signs of breaking. I imagine it might be used as strings for some kind of musical instrument, it makes quite a nice sound when plucked under tension.