Poly Glow Phosphorescent 40wt Embroidery Thread 109 Yards. POLY GLOW is a phosphorescent, washable embroidery thread that stores UV and artificial light, making embroideries and seams glow in the dark. The thread is extremely well-suited for extraordinary effects on sports, kids, and leisure wear, bags and satchels as well as for embroidering logos and letterings. Recommended needle size: 70-80. 1 Spool of Poly Glow Art. 2097. 109 yards No. 40. CHK-2927-1260