Bests & Worsts Reviews from Amazon

Since there is so much concern about reflectivity I thought I'd set up a photo and show six options. This is a flash photo taken at night. The far left sample is Blue Water 3.5 mm reflective nylon cord. It is smooth and soft, as you would expect Kernmantle cordage to be; the reflective threads are very bright, but there aren't a lot of them. Its breaking strength is 500 lbf. (2.2 kN). Next is 2.5 mm Nite Ize. This cord has more reflective threads and they kinda stick out on the surface. It reflects the most light of all the cords, but its dark green color is hard to see in daylight. It feels kinda stiff and lumpy in the hand rather than flexy. Next is the 2.0 mm (as I measured it) "fluorescent" Reflective Guyline. It has fewer reflective threads and less reflected light, but its non-reflective fibers are bright yellow-green, so it stands out well when illuminated. There's no identification of the material, but assuming it's nylon, the tensile strength would be about 175 lbf. (0.7 kN). And assuming it's nylon it may stretch a when wet. Then we have 1.5 mm Kelty TripTease. Its gold color stands out and its reflective fibers work well. TripTease is reputed to have a breaking strength of 188 lb, due to its Dyneema core. It is what I use most of the time for tent lines and zipper pulls, and the Dyneema core seems to minimize stretch when wet. It works well with Lineloc tensioners. Next is non-reflective yellow Dyneema cord. It is oval, but about 2 mm on average. Kite line like this has a tensile strength of about 4 kN (900 lbf), so breaking won't be an issue, nor will stretch when wet. The problem is that it doesn't hold knots well, but it works well enough with the Lineloc connectors. But if you really want a SUPER reflective line, your best bet would be to just clip on a bicycle spoke reflector. You can get them on Amazon for about .30 each and they fit the ~2 mm cords readily; they can be slid up and down but they stay in place. They only weigh 1 gram. Even half of the 2" length would be very bright by headlamp. So I'd say that the hot ticket would be a Spectra/Dyneema cored line with yellow polyester sheath (to make knots hold better). You can get it here on Amazon by looking for Spectra Survival Cord; it costs about the same <$15 for 50' as similar cordage. At about 2 mm, it breaks at 325 lb. Clip on a few bicycle spoke reflectors and you're good to go. There are other options, if you want to look around. New England Ropes makes Spiderline Dyneema core cords with polyester sheath; the 1.8 mm breaks at 350 lb. You can find a wide variety of spiffy cords and LineLoc and Micro LineLoc connectors (and lots more) at zpacks; that's where I'd start looking.