40wt. 700 yards per bobbin Glow-in-the-dark thread used for sewing, quilting and embroidery. This glow in the dark thread is a top quality product made in USA, in polyester. This specialty product is perfectly sized and priced for any machine or any budget. Heat Sensitive. Do not dry clean, iron, place in the dryer, or use with bleach. Be creative in your next project and try some our special glow in the dark Thread for an original glowing effect. This embroidery thread provides the same high quality as all our other products.