ChalkMarker, water-soluble, wetwipe, chisel tip, line width 2 - 5 mm, 1 piece, black. Intense, bright colour, good opacity, ideal for use on glass boards and chalk boards. Water based chalk ink, wetwipe, can be used on all non-porous surfaces such as glass, perspex, plastic and metals. Shake before use until you can hear mixing balls. Open cap and pump until tip is moistened.