The new glow in the dark threads are pretty neat to see stitched out. I bought a spool that I thought was a dud because it didn't glow very much even after setting it under an incandescent light. I did some digging and review reading and learned that to get them to glow the brightest the spools need to sit under either a florescent light or LED light for at least 24 hours. I stuck my spool under my Ott light for 24 hours and lo and behold - it worked! Now when I turn off the lights in my sewing room the little spool of glow in the dark thread sits there shining away.