Permanent marker is designed to work on almost any surface - indoors and outdoors - including cardboard, metal and plastic. Ink resists rubbing, water and fading to deliver marks that last. The ink is low-odor, nontoxic and certified. Quick-drying formula minimizes accidental contact with damp ink. A chisel tip allows you to vary the width of your strokes for legible notes on small surfaces and broad strokes on high-visibility signs. Nontoxic formula allows safe use by children.