Our all-purpose invisible blue marking ink is non-porous and non film producing. These inks are water clear, abrasion resistant, and produce a strong brilliant fluorescent colour under black light activation. Our inks are used to mark metal, plastic, wood, concrete, marble, rocks, just about anything where you need a strong, incredibly durable invisible mark. Used extensively for sting operations, ownership, and product proof. These products produce a coating that is water clear on the desired object. Applied thin enough you will not even see the coating itself as the solvent base fully evaporates.