Glow in the Dark Bouncy Balls

My kids love anything colorful and messy, so I'm always on the lookout for gooey projects! We've explored slime before, so I knew we also had to check out these glow-in-the-dark bouncy balls. My kids were thrilled to find out we could make our own and bounce them in the dark! Borax (sodium tetraborate) is a naturally-occurring mineral salt commonly used as a laundry booster or cleaner. As with any other cleaning product, it should be kept away from children not under direct supervision of an adult. Do not allow children to ingest Borax. If consumed, contact a poison control center immediately.

  1. Ages: 5 - 16

  2. <30 minutes

  3. Super messy

  4. Grownup needed


Step-by-step tutorial

  • Step 1

    Mix 1/2 tablespoon of borax with 1 1/2 cups of warm water. Stir your borax solution with a craft stick until most of the powder has dissolved.

    Photo reference of how to complete step 1

  • Step 2

    In another cup, mix 1 tablespoon of glue, 1 tablespoon of cornstarch, and 1 teaspoon of fluorescent paint. Stir well with a new craft stick.

    Photo reference of how to complete step 2

  • Step 3

    Add 2 tablespoons of your borax solution to your cornstarch and glue mixture. Stir the mixture with a craft stick for about a minute. As you stir, you'll see a sticky, slimy material start to form around your craft stick!

    Photo reference of how to complete step 3

  • Step 4

    Time to get messy! Pull the slime off of your craft stick and knead it with your hands. If your slime is really sticky, dip it into your borax solution and it'll get smoother. Once you've worked your slime in your hands for a few minutes, it should start to dry and harden. Roll your slime up into a ball and try bouncing it on the ground! If your slime isn't bouncy enough, try using less cornstarch or more glue. Keep experimenting for the perfect recipe!

    Photo reference of how to complete step 4

  • Step 5

    To get more color, try making several slime balls with different colors of paint. Tear off parts of each ball and mix them together. To make swirling patterns of color, squeeze, and stretch the slime!

    Photo reference of how to complete step 5

  • Step 6

    Shine a blacklight on your slime balls to make them glow. What's going on? This project uses a "black light" to make a glowing bouncy ball. Black lights look a little bit purple, but it's the light they produce that you can't see that's really interesting. Black lights produce ultraviolet (UV) light. Our eyes can't perceive UV light, but our skin can feel it; UV light is the reason we get sunburns. Some substances, like fluorescent paint, will glow under UV light. The paint absorbs the energy in the UV light, and then emits it as visible light. Groovy!

    Photo reference of how to complete step 6

  • Tip

    Keep in mind your slime balls will keep hardening as they dry out. You can store them in an airtight bag to save them.

You might also like

Top categoriesBurst graphic

Share what you made & tag us at!