There's a reason Sharpie® is a household name. From marking metal to wood to sandwich bags and more, these permanent markers have been gliding on posters, mirrors, CDs, and virtually anything else for decades. They are also developed with an AP-certified non-toxic formula - making them safer to use in the home or the workplace. Oh, and the quick-drying ink reduces the chances of smearing or smudging while the ultra-fine tip delivers clear, visible strokes and a smoother writing experience. It's a Sharpie®! Perfect!