The Pentel Arts Wet Erase markers feature chalk-based ink that adheres to sealed, non-porous surfaces such as glass, windows, mirrors, metal, plastic and porcelain while remaining opaque. Once dry, The ink remains intact when exposed to Raindrops. Turn windows, mirrors and glass into works of art, special announcements or more. Customize plastic containers for easy storage labeling. Ink wipes off with a clean, damp cloth. Available in a variety of colors in chisel or JUMBO tip. Acmi certified nontoxic.