
It's finally there!! Blue and Yellow mixing to make Green! They will continue to mix until all of the cups have equal water levels.
We were way overdue for a fun experiment, so this morning I broke out the materials for a paper towel experiment that I saw on Pinterest.
- 3 clear cups
- Enough water to fill 2 of the cups
- Food coloring
- Spoon to stir
- Paper towels
This was so simple and worked like a charm! I put 3 plastic cups in front of Lorelai – 2 filled with water, 1 empty. I asked her how she could get the water into the middle (empty) cup without touching the other cups at all. All of her ideas required touching the cups. I then told her about the paper towels and how it would suck up the water and transfer it to the middle cup. She didn’t believe me, so we went ahead and started the experiment.
- Fill 2 of the cups with water.
- Add food coloring to each one and stir. We did yellow and blue.
- Roll a paper towel into a tight tube.
- Stick one end into one of the colored waters, and the other end into the empty middle cup.
- Repeat for the other side, so that each cup has a paper towel that ends up in the middle cup, as seen above.
- Observe the water moving up the paper towel. Ours took a while to get down into the other cup (like 30 minutes). We didn’t sit there the entire time since mosquitoes were swarming around us. We checked back in every ten or so minutes.
The original website shows that you can do this with only 2 cups with just one color – the paper towel will keep transferring the water until the water levels are equal in both cups. So neat!

Hello,
I’ve done this activity with girl scouts and they always love it. Now, I am compiling resources for other leaders to use. Would you mind if I linked back to this activity and included a picture of it? Thanks in advance!
That’s fine, Suzanne! Thanks for asking.