After the protected item comes in contact with the skin, the body's amino acids react with the powder, creating a highly visible colored stain which can last up to several days. For example, an article can be marked so that it is invisible to the eye, but under ultraviolet light the item and anyone who touched it can be identified. Powder, once touched, remains on fingers and hands, invisible except under UV light. Tampering, theft, substitution, etc., can be revealed as well as evidence against a suspect provided. Fluorescence is the phenomenon by which certain materials absorb ultraviolet energy and re-emit this invisible radiation in the form of visible colored light.
Fluorescence occurs only while the material is being activated by the UV rays.
To make an ultraviolet paste, simply mix the powder in Vaseline. 2 oz. container. Its convenient coat pocket size makes it as practical in the field as in the lab. It also has a standard white flashlight bulb built in. This felt-tipped pen provides you with an inexpensive and convenient ultraviolet writing instrument.