Invisible UV Inks for Pens and Stamp Pads

UV inks that are invisible under normal light, but can change colors as shown in the photo below, when exposed to UV (black) lights.

These inks are suitable for use in writing instruments like refillable pens, fountain pens and stamp pads.

Fact that these inks cannot be seen under normal light, or in the dark; and can only be seen when there is a UV Black Light source present! makes it an ideal product, for product identification.