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?
That’s what I intend to try this year.
Do you have some experience with it?
I use the MLH micro tensioners. I’ve used Atwood cord and it is a great product, but the only experience I have with the GITD version is seeing it use by others once or twice and it seems to hold a glow reasonably well.
I have no idea about availability in Poland however.
Thanks, you seem to be the first person recommending a glow rope while having some experience with one.
The cost is quite high so it will be at the end of my list of the things to try - but I will put it there.
One caveat, I’ve only seen the GITD relatively early in the evening. If your main concern is drunks stumbling around at 2 AM, I have no idea how well it is still glowing at that point.
Honestly I’d probably just hang a red fauxton from the middle of the guyline.