1. CH6009 invisibkle ink pen 2. Show 3 visible color to UV black ... 4.Ideal gift CH6009 Permanent UV Marker-uv light invisible ink pen:OEM service & buyer's logo are welcomed!1. ... Non-toxic, Environment Friendly,2. Its permanent UV ink is invisible to the naked eye, and it’s only visible ... glass, paper, wood, fabric, plastic, etc.Note: This invisible ink pen, is only be visible under UV light, it is ideal ...