Made to the exacting standards of Colorful thread, this 100% polyester thread is combined with ‘glowing agent’ to produce a photo luminescent embroidery thread. When exposed to as little as 15mins of natural light the thread glows in the dark. Glow in the dark thread Is fully washable and colourfast. It is a slightly thicker denier than our standard colours so depending on preference a larger needle is recommended and a reminder to set your machine at a slower speed. This product is ideal for baby or nursery items, security companies, mining, night clubs, sporting events, band performances Etc.