Optical White Glow In the Dark Machine Embroidery Thread,150D Fabulous/Moon glow thread,3300Yards 150D/2 Polyester Filament Thread Contains 3300 Yards of thread In Optical white color Charging the thread with natural or artificial light for a few minutes, then it can glow in the dark for several hours For Machine Embroidery/Sewing, adding highlights to your project. The more thread you put in an area, the more glow you will get