Want a Halloween effect that makes people stop and ask, “How did you do that?”
This simple trick transforms ordinary water into a brilliantly glowing Halloween display. Under a black light, the color can look so intense it resembles fluorescent paint—perfect for creating that eerie, straight-out-of-a-movie atmosphere.
The secret? Highlighter ink, water, and the right lighting.
What You’ll Need
- A few water-based fluorescent highlighters in your chosen color
- Room-temperature water
- A UV-A black light intended for decorative use
- A waterproof decorative container
- Disposable gloves
- A stirring stick
- Pliers, if needed to remove the highlighter’s end cap
Color tip: Test your chosen highlighter under the black light first. Different colors and brands can produce different results.
How to Make Glowing Water
1. Prepare your workspace
Protect your work surface and put on disposable gloves. Highlighter ink can stain, so use a container reserved for crafts and decorations.
2. Open your highlighters
Carefully remove the end cap and pull out the ink-soaked felt reservoir inside. An adult should handle this step. If the casing won’t open easily, try another marker rather than forcing it with a sharp blade.
3. Let the ink soak
Place the felt reservoir in the water and let it soak for about 30 seconds to begin releasing its color. Some markers may need a little longer.
4. Squeeze out the color
With gloved fingers, gently squeeze the reservoir over the water. Ink can come out of both ends, so keep the entire piece above the container.
Dip and squeeze again until most of the ink has been released, then remove the reservoir.
5. Stir and adjust
Stir the water until the color is evenly distributed.
For a richer effect, add ink from additional highlighters a little at a time. Check your mixture under the black light as you go so you can find the appearance you like best.
6. Bring on the black light
Secure your black light overhead or aim it toward the liquid from the side, keeping the fixture safely away from splashes.
Dim the surrounding lights, adjust the angle, and watch the transformation. The vivid fluorescent color creates a striking special effect with surprisingly simple supplies.
Getting That Movie-Magic Look
A darker setting helps the glow stand out. Position the black light so it reaches the liquid directly, and experiment with its angle before adding more ink.
The intense, paint-like appearance is a visual effect: the mixture still flows like water. Results will vary with your highlighters, dilution, lighting, and container.
Why Does It Glow?
Fluorescent dyes in the highlighter ink absorb ultraviolet light and release visible light, creating that dramatic glow.
Keep the black light on during your display—the liquid won’t continue glowing once it’s switched off.
A Few Important Precautions
This mixture is for decorations only. Do not drink it, apply it to skin, heat it, or use it in fog machines, humidifiers, or misting devices. Keep it away from children and pets.
For a decorative fountain, check that the manufacturer permits dyes; ink can stain the basin and affect its components. Keep electrical equipment dry, follow your black light’s instructions, and avoid looking directly into it.
Make Halloween Unforgettable
A little creativity can turn simple supplies into a scene your guests will remember.
Bring your Halloween vision to life with costumes, accessories, props, and décor from Halloween Utopia—your Online Halloween Superstore.