invisible inkCan seal on all surfaces:Glass,Ceramics,Paper, Wood, Plastic , Cloth and etc.,Waterproof,Non-toxic,Long-lasting,Ev- This Photo show that effection of seal on glass fish Aquarium under UV black light Invisible usually,but clearly show to wicket tellers, detectives, pawn shop owners and police when under the black light! It can also be used to stadiums, theaters, bars and so on,also ...