Salt and Watercolor Trees
Students will see what happens when you add salt to wet watercolor paint.
By Kim Swanger [Kim is a K-3 art teacher from Council Bluffs, Iowa.]
This lesson addresses the art element of texture using the science of chemical reaction.
What You Need:
- Table salt
- Cups of Water
- Watercolor Paints
What You Do:
- Start by asking students to define the word “texture”. Have them describe the texture of their clothes. Write down the words they use to describe textures.
- Explain how texture can be visual. Provide examples using illustrations from story books if copies of artwork are unavailable. An illustration by Lois Ehlert is usually very flat (Chica Chica Boom Boom) while a picture from any of Marc Pfister’s books (Rainbow Fish) has a sense of texture. Have students describe the textures they see.
- Demonstrate the technique you are asking the children to learn. Make a picture of a tree using watercolors. You can be somewhat sloppy and make the tree look fairly “cartoonish”. This tree has little texture and looks pretty flat.
- Lightly sprinkle salt on the picture while it is still wet. Watch the texture increase as the salt absorbs the water around it but leaves the pigment behind. This takes just a few minutes. The chemical reaction leaves light spots where the salt grains landed.
- Ask the students to describe how the salt added texture to the tree. The tree will seem to have bark and leaves as a result.
- Encourage the students to create their own trees. Emphasize that they may wish to paint in steps since the salt MUST be added while the paint is still wet. Tell the students they must allow the picture to dry completely before attempting to brush off the salt.
NOTE: It is important to explain to students how the salt affects the paint. You may with to emphasize the idea that salt absorbs water by asking students how they feel after eating very salty chips or popcorn. They get thirsty because the salt absorbs the water in their bodies just like it absorbs the water in their paintings.
This technique is also useful in creating landscapes of night scenes. For example, you can use crayons to create a daytime rendition of Van Gogh’s Starry Night painting. Wash over the crayon with a dark blue or purple watercolor paint. Then sprinkle salt over the dark paint to see stars appear on the paper.