April 13, 2021
Use spring flowers to explore the science of pigments
Did you know you could make paint using flowers?
Did you know you could make paint using flowers? Flowers have different colors depending on the pigment found in their petals.
Pigments are substances that selectively absorb certain wavelengths of light and reflect others. The wavelengths that are reflected determine the colors we see. So, for example, the petals of a red rose absorb everything except red wavelengths.
People have used plant pigments to make paints and dyes for thousands of years. Follow the directions below to make your own paints out of flower petal.
- Flowers petals separated by color
- Boiling water
- Small bowls
- Muddler or wooden spoon
- Lemon juice
- Baking soda
- Empty egg cartons (optional)
- Go outside and find some flowers! Make sure you don’t pick flowers that belong to anyone. Try hunting for flowers in your own backyard or searching for flowers growing wild in a local park. Try to pick the flowers right before you make your paint so they are as fresh as possible.
- Remove the petals from your flowers and separate them into individual bowls. Make sure to wash your hands after handling any wild plants.
- With help from an adult, pour boiling water into each bowl. Only pour enough water to soak the petals; too much water will over-dilute the pigments.
- Using the muddler or the back of a wooden spoon, gently crush the petals to release the pigments into the water. You will probably start seeing the color of the water change right away. Crush until your petals form a pulp.
- Leave the petals to soak for around 30 minutes.
- After 30 minutes, come back and try out your paints! You do not need to remove the petals from the bowls, they will continue to release pigments as they soak.
- After you have tested your paints once, it’s time to experiment with chemistry!
- Pour a small amount of each color into two containers. Empty egg cartons work well for this part or you can use any small containers you have lying around.
- Once you have each color separated, try adding a drop or two of lemon juice to one container and see what happens to the color. Compare it to the original color. How has it changed?
- Mix a tablespoon of baking soda with an equal amount of water to make a solution. Add a tiny bit of the baking soda solution into the third container of color. How does that color compare to the original and the lemon juice colors?
- Repeat the process with all the colors you made and see how many different colors and shades you can create. Observe what happens to your painting over time, do the colors look the same after they dry?
Crushing the flower petals in the water released the tiny molecules of pigment and dyed the water. The longer the petals soak, the more pigment is released. Pigments of different colors have different chemical makeups. Flowers with red petals tend to be more acidic, while blue and purple flowers tend to be more alkaline.
Adding an acidic or alkaline substance to a pigment will cause a change in its pH, which can change the color we see. Lemon juice is acidic and baking soda is alkaline, so when we add them to our paints a chemical reaction takes place and changes the color of the pigment.
Try experimenting with the amount of baking soda and lemon juice in each container. What do you think would happen if you added some lemon juice to one of the baking soda paints? Have fun experimenting with the chemistry of color while also creating beautiful flower petal art!
Plus, check out another Stay At Home Science activity to learn how to paint with vegetable scraps.