Refective cord

Lawson Glowire is very good.

^agreed. Glowire is great and has a very nice stiffness that keeps it from tangling and makes tying/untying knots very easy.

Also MLD’s thicker line is very nice and has a reasonable amount of reflective strands.

If you want something thinner/lighter, I recently picked up a hank of Paria’s 1.5mm cord and it has a nice reflective tracer and is fairly stiff for a thin cord. I haven’t used it on a shelter yet but it seems very promising.

Ditto that – Lawson.

Hammock gear.. reflect cord.  Black, dark olive or brown. Lights up pretty sick at night when you hit it with flash light. Even from a distance… i use it on my hammock tarps so I dont get lost at night when wandering away from my campsite. Also used it on my ground tarps and bivies.

I tend to favor bright colors over reflective options, but kelty triptease works well enough.

I also recommend Hammock Gear reflective cord. Its stiff so it doesnt tangle easily, is very reflective, and knots easily. It also works with LineLoc3’s very well.

https://hammockgear.com/reflective-guy-line-50-ft-hank/

Another vote for Lawson Outdoor Equipment’s “Reflective Glowire”. Shows up really well from 100-200 feet away if you’ve got a headlamp on.

Here’s the all-important specification for the 2 mm: 50 feet = 55 grams.

They make a 2mm and a 3mm but for tent guy lines, the 2 mm is as much as I’d ever use – I’d prefer 1.5 mm which is still bigger than the 130-pound test Dacron line I’ve got on many of my shelters.

The 3 mm would be better for bear hangs since it wouldn’t cut into the branch (as much).  Assuming the bear doesn’t have an headlamp to help find it.

I’ve found the 1.8mm version from Paracord Planet a good one: