Just few minutes of being exposed to light & the beautiful pastel colors glow powerfully in the dark for up to eight hours.  Luminary’s consistent elongation & high tensile strength offer optimal performance.  The glowing effect is diminished after each wash, ironing & dry-cleaning session. Luminary has successfully passed 50 wash tests while still retaining some of its glowing power.  640m / 700yd on each mini cone.