Magic Paper Towel Experiment: Hidden Rainbow Science for Kids
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What if you could draw a rainbow… hide it… and then make it magically appear?
This magic paper towel rainbow experiment is a simple science activity that surprises kids every time. With just markers, paper towels, and water, a hidden rainbow slowly reveals itself right before your eyes.
It feels like magic, but it’s actually a great way to explore absorption and capillary action.
What Is the Magic Paper Towel Experiment?
The magic paper towel experiment is a simple science activity where a drawing hidden inside a folded paper towel appears when water is added.
As the paper towel absorbs water, the ink from the markers spreads through the fibers of the towel and becomes visible on the other side. Kids are always amazed when the hidden picture suddenly shows up.
This experiment works well for:
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preschool and elementary students
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homeschool science lessons
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classroom demonstrations
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quick STEM activities
Supplies You’ll Need
This experiment uses simple materials you probably already have at home.
- paper towels
- washable markers
- sharpie marker
- shallow dish or tray
- water
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How to Do the Magic Paper Towel Rainbow Experiment
1. Draw Your Rainbow
Lay a paper towel flat on the table. Use washable markers to draw a rainbow on one half of the paper towel.
Make the colors bold so they will show through when the water spreads. I did an outline of a rainbow with the color underneath.Â
2. Hide the Drawing
Fold the blank half of the paper towel over the drawing so the rainbow is completely hidden inside the fold.
Now the picture cannot be seen.
3. Add Water
Place the folded paper towel into a shallow dish with a small amount of water. You can also drip water onto the towel using a dropper.
4. Watch the Magic
As the water spreads through the paper towel, the rainbow will slowly appear through the paper. Kids love watching the colors move and spread across the towel.
The Science Behind the Magic Paper Towel Experiment
Even though it looks like magic, this experiment is actually demonstrating two scientific processes:
Absorption
Paper towels are designed to soak up liquids. The tiny spaces between the fibers allow water to move easily through the towel.
When the towel touches water, it quickly absorbs the liquid and spreads it throughout the material.
Capillary Action
Capillary action is the process that allows liquids to move through small spaces without the help of gravity.
In this experiment, water travels through the tiny fibers of the paper towel. As the water spreads, it carries the marker ink along with it. This allows the hidden rainbow to become visible through the paper.
Capillary action is also the same process that helps plants move water from their roots up into their stems and leaves.
How Is This Different From the Walking Water Experiment?
You may have seen the walking water rainbow experiment, where colored water travels between cups using paper towels.Â
While both experiments demonstrate capillary action, they show it in different ways.
In the walking water experiment, water moves between containers and mixes colors. In the magic paper towel experiment, the paper towel absorbs water and spreads the ink from a hidden drawing.Â
This activity focuses more on absorption and ink movement through the paper fibers.
Try These Fun Variations
Once kids see how it works, they will want to try it again.
You can experiment with:
• drawing secret messages instead of rainbows
• creating hidden pictures
• writing words that appear with water
• trying different marker colors
Kids love guessing what will appear when the water spreads.
Why Kids Love This Experiment
This activity is perfect because it is:
• quick to set up
• visually surprising
• easy for young learners
• great for introducing basic science concepts
It’s also a fun way to turn everyday materials into a simple STEM activity.
More Simple Science Experiments for Kids
If you enjoyed this activity, try these experiments too:
