What are they for? These are most commonly found in small businesses, cafe's, restaurants, bars, butchers, patisseries and more. How do they work? The pens are fitted with special fibre tips, with a built-in pump action mechanism. You simply push the tip against the paper several times to get the ink special ink flowing from within the pen. The ink is water-based and highly opaque, suitable for writing on surfaces such as glass, chalkboards, plastic, metal and more. Once your design needs updating, you can imply wipe away the original with a damp cloth, let the area dry and then create a new design.