This image was produced by drawing a smiley face with Vaseline onto a white cutting board and turning on a black light.
Glowing Petroleum Jelly
From Anne Marie Helmenstine, Ph.D., About.com
Petroleum jelly, such as Vaseline, glows bright blue under a black light. Anything you paint with the petroleum jelly will glow blue under ultraviolet light.
Anne Helmenstine©2009 About.com, a part of The New York Times Company.
All rights reserved.