Secret of colors

Has this ever happened to you? You’ve drawn a nice, colorful picture with felt-tip pens, and then the picture accidentally gets wet. The paper curls and the colors suddenly run. Strange – now you can see completely different colors. Where did they come from? Are there other colors hidden in the felt-tip pens?

Before you get started

If you are experimenting at home:
1. Let your parents know and discuss the experiments with them beforehand.
2. Do not eat or drink at your workspace.
3. Wash your hands thoroughly before and after the experiment.
4. Be careful and cautious with the materials.

Graphic figure boy pouring liquid in flask

measuring jug, felt-tip pens, scisso, coffee filter and glas bowls

You will need

Coffee filter
Scissor
Felt tip pens
Two small bowls
Water

Let’s get started!

1. Prepare paper strips

Cut a rectangular strip as long as possible from a filter paper.

paper stripe with colorfuls dots in front of two glass bowls

2. Colorful felt-tip pen dots

Draw a line of dots on the strip using different colored felt-tip pens. The dots must be at least 0.5 cm apart. Fold the strip on both sides as shown in the photo.

paper stripe lays across two glass bowls

3. Fill with water

Place the strip over two bowls so that one end extends into one bowl and the other end extends into the other bowl. Fill one bowl with enough water to wet the bottom of the strip.

paper stripe showing colorful traces laying across two glass bowls

4. Observe

Observe how the water is slowly absorbed by the filter paper. It moves through the paper into the second bowl. Be patient, it may take a little longer to see anything.