I have ordered several different yarns that glow. They are very different. One skein looked great but after one project it quit working.
I thought about why and realized what did it. I had made the first project with the skein and then rolled the rest into a ball.
As I rolled it the 'glow' layer must have rubbed off on my hands. So it was just a finish that wasn't permanently in the yarn.
I've noticed that certain colors seem to shine brighter. Green is the best typically. Yellow and orange are good as well. Purple and blues don't seem to glow too well.
I haven't tried every color of this yarn, but I have ordered a lot of glow paints, markers and other products and so far that has held true.
I also noticed that certain light sources cause them to glow brighter. My son has a flashlight with high lumen count. When I use that to light up these yarns they show really well, especially if the light source was very close to the yarn for a minute. Then when we use regular house lights, it's not so bright.

One tip from experience is to make items that aren't going to be needing laundering. That seems to ruin the glow.
I would make a hat, but not gloves, socks etc. I made some cute chapstick holders that glowed for some younger girls and they loved them. It was fun to see them glowing in an otherwise dark room.

It's a novelty item so it's not sold for it's high quality yarn properties. So I'm rating it for it's fun factor.

This is an interesting concept and works well. It is great for kids projects. My daughter and mother in law seem to be enjoying incorporating it into their projects so that's enough for me.

So cool

This is decent yarn. It glows well enough and is easy to work with. I just wish it was a little softer.

Typically any yarn that says it glows doesn't have a bright effect unless it's a white color. This is not the case for this yarn. It is SUPER bright and absolutely beautiful and the dark when it's charged up. Best way to get the brightest effect is by sitting in the sun (ironically) and then going into a darker space. Highly recommend for anyone who's looking for a unique yarn to add to their collection. Just keep in mind it is on the rougher side of texture.