Did you know that many laundry detergents glow in the dark? Most of them contain phosphors, a powder that glows or “fluoresces” under ultraviolet light AKA black light. Use them to paint hidden pictures that are only revealed in the dark!
- Liquid Laundry Detergent Test a small amount of detergent under a black light first to make sure it contains phosphors. We used the Trader Joes liquid laundry detergent.
- Black paper
- Paint Brushes
- Black Light You must use a fluorescent black light. Incandescent black light bulbs are not powerful enough. We bought this light a few years ago and have used it for many glow-in-the-dark projects since then.
- Pour laundry detergent into a container.
- Use the detergent like paint on black paper
- Let dry. The images should fade.
- Go into a very dark room with a black light, Hold up your pictures near the light. They will glow!
Paint some hidden messages for friends and family!
Why are there phosphors in detergent? Curious why something you use to clean your clothes contains fluorescent powder? The phosphors are used to make whites appear whiter when seen in bright light by adding in a touch of blue.