Customized Pens, Kikkerland Invisible Pen Light - UV Light, Can you keep a secret? You will be able to with the Kikkerland invisible ink pen. Write secret messages, passwords or your mother's maiden name and it will only be revealed by the UV light in the tip of the pen. ABS, aluminum and plastic and an enclosed battery will allow you to keep secrets. ... #K-W4434 $8.77/each.
