A collaboration between Sewful Therapy and W+W Co:
This thread is 100% polyester and was sourced specifically to offer a glow option that wasn’t better suited for embroidery. Get something that will perform properly for its intended use because we can be tough on our bags!
Use UV light to “charge” the glow before viewing results. A black light gives the quickest results, but you can also set it in the sun.
Tex 50 is about the max end of what domestic machines can handle, but you all know your machines best so your results may vary. Each spool is 1800m.
Tex 67 is intended for industrial use, but again, YMMV. Each spool in this size is 1350m due to the larger diameter of the thread.
For reference, the basic Gutermann Mara 100 is a Tex 30 thread and the Gutermann Mara 70 is a Tex 40, so the Tex50 thread is a little thicker than that. I would personally use a universal or topstitching 100/16 needle with this thread. (Don't... don't... don't use leather needles on vinyl!)