A very colorful journey

Are you ready for an experiment that will reveal a property of water known as capillarity?

For this colorful experiment you will need the following materials:
✔ Water
✔ 3 or more short glasses (for every pair of glasses you will need an empty glass)
✔ Kitchen paper
✔ Food coloring (3 different colors)


First, cut the kitchen paper into quarters to fit between the glasses as follows: Each end of the paper should go from the bottom of one glass to the next without much space between them. Set the paper aside and move on to the second step.

Fill a glass with water and add different colored food coloring to each glass, leaving an empty glass between each glass. Then place the previously cut kitchen paper between the glasses. If at the end of the procedure, the water does not displace in a few minutes, it means that you need more water.


As you may have noticed, the colored water rose through the kitchen paper and reached the empty glass. For its part, the empty glass was filled with water until the water levels of all glasses were equal. This path of water through the paper is due to a phenomenon called capillary action. Capillary action is the ability of a liquid to flow upwards, defying gravity in tight spaces. It is the same action that allows the roots of a plant to transport water to the leaves.

Kitchen towels and all paper products are made from fibers known as cellulose, which are found in plants. In this demonstration, the water flowed up through small spaces between the cellulose fibers. The holes in the kitchen paper acted like capillary tubes, lifting the water.

You can change the level of water or volume in the glasses and observe how it influences the travel time of the water or leave the same volume, but change the brand of towels.

You can also change the elevation of the vessels and see how it affects the results. For example, place one of them on a book. It all depends on your imagination!