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Paper Towel Rainbow Experiment
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How to Grow a Rainbow

Try this easy grow a rainbow experiment for kids! Watch rainbow colours travel up a paper towel using markers and water. It's a fun STEM activity with a bit of magic to it!
Active Time20 minutes
Total Time20 minutes
Yield: 1 rainbow paper towel
Author: Debbie Chapman
Cost: $1

Equipment

Materials

Instructions

Step 1: Find what you need

  • Gather your supplies and materials.
    Grow a Rainbow Experiment Supplies

Step 2: Draw rainbow colours on paper towel

  • Cut a piece of paper towel to be 7 inches long and whatever width will fit in your glasses (we made ours 2-1/2 inches wide).
    You can generally get 2 rainbows from 1 piece of paper towel.
    Grow a Rainbow Experiment
  • Begin by drawing a red rectangle on one end of the paper towel with washable marker.
    Draw your rectangle about 1 inch long and just wide enough so that all the colours of the rainbow will fit equally on the end.
    Grow a Rainbow Experiment
  • Repeat on the opposite side, so the red section is across the paper towel from the first rectangle.
    Grow a Rainbow Experiment
  • Repeat, filling in the rest of the paper towel ends with rainbow colours.
    Go in order using red, orange, yellow, green, blue, and purple OR red, orange, yellow, green, blue, indigo, and violet -- depending on what colours of marker you have.
    Grow a Rainbow Experiment

Step 3: Insert the paper towel ends into water

  • Fill 2 glasses of water between 1/2 and 3/4 full and set them down next to each other.
    Grow a Rainbow Experiment
  • Place one end of the paper towel in one cup and the opposite side in the other cup.
    Grow a Rainbow Experiment
  • Watch as the colour immediately begins to spread up the paper towel with the water.
    (You may also see some of the dye go into the water like little fireworks, depending on if the marker is still wet on the paper towel and how deeply the ends are dipped into the water.)
    Grow a Rainbow Experiment
  • Continue to observe the colours traveling up the paper towel to make the rainbow connect in the center.
    This process will take between 10 and 15 minutes.
    Your grow a rainbow experiment is complete! Now have fun discussing how the experiment works (read more about this below).
    Grow a Rainbow Experiment

Video

Notes

Looking for more rainbow crafts? Here's a few of our favourites:
Rainbow Squeegee Painting
Rainbow Sensory Bottles with Water Beads
Paper Strip Rainbow