Invisible Pens Come in 3 INK COLORS! - Kids Party Toy Markers - Disappearing Ink Pens with UV Dark Light on Keychain - Awesome Stuff for Secret Message Writing - A Magic Secret Agent Spy Pen! Experiment with Your Invisible Inks on T-Shirts, Jeans, Tops and Richly Colored Paper to Create Amazing Results! Bright & Bold Pink, Blue, Yellow Fluorescent Inks Write on Paper, Fabric, Skin, Glass, Plastic, Wood, and Most Dry Surfaces! A Perfect Gift for Your Secret Agent Birthday Boy or Girl - Secret Message Writing - Discreetly Mark Wedding RSVP's - Mark Valuables. Invisible Ink Markers Light Up with the UV Light (included). Non-Toxic, Environmentally Friendly, High Quality, Long Lasting, Waterproof. Make an Ordinary Day, Extraordinary! We Stand By Our Products 100%, by Sherlock Hones. We've Got Your Back!