How about cheap “throwies” (with resistor) ringed around each cord to slide down to the base?
It won’t light the rope, but will at least show the “footprint” of the tent-area.
GITD Paracord vs GITD Tape
This “test” was conducted by putting some UV light shinning above both materials and then a Wuben T70 (± 4200 Lumens) .
After shining the lights (left) and after 20 minutes (right)
The rope cannot be seen almost! Even at naked eye. I located the place through the GITD tape.
How about tying white ribbon onto the lines?
the cheap GITD tape is very good - i’d just get some of that and put a few rings of it around my ropes
it will seriously glow all night
wle
Never played with it, but sounds like EL wire might due the trick. Here is some info:
https://learn.sparkfun.com/tutorials/getting-started-with-electroluminescent-el-wire/all
or, can thick fishing line carry light from a 5mm led?
Lots of nice input, thanks. 
Man Without Shadow, do you have experience with these ropes? So far everyone who actually tried the stuff shows disappointment…
I’d rather have something inexpensive and cheap-looking. For 2 reasons.
A large part of what I like in the festival is not having to care. The less stuff I take, the less it’s worth the more free I am to enjoy myself.
The other reason is crime.
On average there are roughly 500 000 attendees to the festival (though it swings a lot). With so many people sleeping in tents, often drunk or having fun at concerts away from their places - there are thieves as well. Being (and looking) cheap is a good strategy…and a very common one, people just don’t take much stuff there. It’s easy too stand out as a good target. LED ropes, wires and pegs - may be good in general but are not a good idea for my use case.
Throwies are cool, I may try them. 90 cents for 10 LEDs (reusable). $1.5 for 10 cells. Some tape. Before starting the thread I considered spending $20 on a 3mm rope that would likely not work.
Cheap, cheap-looking, likely to work well. I’m slightly worried that it’s cheap looking from up close but maybe not so much from a distance…but I like it nevertheless.
Too late for this year but may try it later.
I really like the idea of using reflective tape stripes. I have such tape so I may try it this year. Even before the festival.
Glowing pegs, fasteners, guy line bands…could be interesting as well, but I’ll leave them for later.
I wonder why do throwies need a diffused LED. I can buy 10 clear red LEDs for $.65. And 5 mm ones are another 10 times cheaper. 
Advice a steel rope 
if you don’t mind a dozen of tripped over, drunk fellas sight in the morning around your tent. Long titanium pegs could be useful as well.
Interesting take.
But I do mind. I don’t want any drunk fella tripping over my tent just because they didn’t think about taking some light before they went on a binge…
And for some weird reason - most tend to think about drinking rather than about lights.
Flood vs throw.
Just get some sandpaper and scuff ’em up.
What about hanging glow sticks from the rope?
Hang a chem light. I bought a couple 50-packs of the small ones to use night fishing (they go in bobbers). They’re cheap enough that when the kids get rowdy I send them in the basement to turn off the lights and play “Star Wars” and throw them at each other.
Yeah, that sticks could work as well.
Though I’m not very fond of replacing them every day. I’ll try othe options first but I’ll keep this one in my head as well.
Thank you!
Those lumaropes look sweet! Thanks for the find gman. The price isn’t that bad. I will add them to my wtb list.
Same experience with the GITD paracord - wasn’t very bright, I bought it thinking it’d make for good guy lines for a tent also, but never bothered using it.
I have a tent with reflective threads in the lines and that works well with only a small amount of light (I guess at a festival there will be some ambient light around to make them show up…)
Other idea would be to leave a light inside the tent, so the tent itself is a little illuminated. That’s my usual trick when camping, so I can find the tent in the dark and have a reasonable idea of where the guy lines should be
I’m not sure if it’s still worth it or if anyone mentioned this before, but here’s something I saw in AliExpress and made me remind this thread:
https://www.aliexpress.com/item/32894563098.html?spm=a2g0s.8937460.0.0.6a162e0erfcsfz
Maybe it is useful for your purposes Agro 
Agro, did you finally pick any of glowing ropes?
Don’t forget to make some pics. I would gladly take advantage of your findings as I’m planing a scouting bivouac with my toddlers…
(Woodstock is just frog’s leap away)
Thanks MascaratumB.
I’m leaving for Pol’and’Rock the day after tomorrow so it’s unlikely to arrive by then. Just like the relfective rope that is on the way. So…for this year I can only try glow tape strips. For the next one - I have a lot of time to collect and test various ideas.
GITD tape isn’t super expensive. Why not apply a few pieces taped over each of the guy lines. Like about 4 or 5 “tags”? Or if you camp frequently, maybe get some cheap GITD markers and use a little duct tape to secure them in place spread across each guy line?