Waterproof stamp refill uv ink ,Non-toxic,Durable,Long-lasting,Enviromental-friendly.Only SHOW once under UV black light Secret refill ink ,can seal on any dry surfaces including: Glass, Paper, Wood, Plastic,Ceramics, Fabrics and Skin etc. ,with common rubber or wood stamps! Invisible usually,but clearly show to wicket tellers, detectives, pawn shop owners and police once under a black light! ...