They stay on until you wipe them off! Use these opaque colored markers on chalkboards, lightboards, windows or windshields, even dark surfaces! Creates a dustless, smooth layer of rich color. Water-based and fade-resistant. Wet-wipe formula is erasable with a damp cloth. Great on black boards, back-lit boards, presentation and metal boards. Medium bullet tips. Fluorescent colors glow brightly under ultraviolet light. Includes fluorescent blue, fluorescent green, fluorescent red and fluorescent yellow. AP Seal, non-toxic.