For Educators

Coffee Filter Rainbows
3.5/5 rating (2 votes)

Materials Needed

Coffee filter; paper clip; black and green water-soluble pens; saucer


1. Fold the coffee filter into half.

2. Fold it again one more time.

3. Draw a dark green line about one inch (2-3 cm) from the round edge of the filter. (Be sure to save room for a black line next to it).

4. Proceed to draw a dark black line one inch (2-3 cm) from the other side of the round edge. (Do not let the lines touch each other).

5. Make the filter into a cone shape by securing the edge of the paper filter with the paper clip.

6. Place water in the saucer.

7. Put the round edge of the filter in the water.

8. Let the filter stay in this position for one hour and then observe the results.


Now, explore! Pay close attention to what happens to the dark green line. Record your observations and explain what you think is happening during this experiment.

What's Going On

Green and black are both combinations of many colors. When the water moves upward, the ink soaks into the filter. The different colors settle in various places on the filter because some colors like the water more than sticking to the paper.

Ohio Content Standards

Physical Science: 1.3, 4.1
OSIC Codes: Y2002.CSC.S03.GKG-01.BA.L01.I03; Y2002.CSC.S03.G03-05.BA.L04.I03
  • Added: November 29, 2011
  • Hits: 11731

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