Expo Vis-ˆ-vis Wet Eraser markers create clear, bright images on overhead projectors and transparencies. They are perfect for use as a template on whiteboards or erasable calendars. You can even use them on laminated surfaces or storage totes. The uniquely formulated ink remains in place until you are ready to wipe it away. It is ideal for scheduling, charting and tracking. It simply wipes off non-porous surfaces with a damp cloth. The ink is certified AP nontoxic.