Rainbow Salt Painting Experiments
Spring is in the air, and with it comes spring showers and beautiful rainbows. This seems like the perfect time to combine a little art and science. Plus kids will love the cool reaction between salt and water color paints. Salt art painting for kids provides an incredible, and gorgeous opportunity for STEAM learning at home or in the classroom!
Salt Art Rainbows: A Fun and Colorful Science Project for Spring
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Whether you’re preparing for a spring celebration or a St. Patrick’s Day craft, salt painting provides an easy and engaging way to explore colors and textures while learning about the science behind it.
What Is Salt Painting?
Salt painting is a really cool art project that can be done in a couple of ways where salt can create interesting textures and vibrant effects when combined with watercolor paints. The salt interacts with the wet paint, causing the paint to absorb the salt and spread in interesting patterns. It can also be used with a glue base to show how water (and paint) will move through the salt trail and spread only as far as the salt goes on the paper.
Salt Painting Project #1 – Salt on Wet Watercolor Paint
What do I need?
Watercolor paints
Salt (table salt, Epsom salt, or sea salt – the coarser the salt the more defined the effect)
Paintbrush
Watercolor paper or thick drawing paper
A small cup of water
What do I do?
STEP 1: Prepare Your Paper
Lay your paper on a flat surface – depending on the age of the kids you may want to tape the corners down to help the paper stay in place and lay flat.
STEP 2: Paint a Base Layer
Paint a layer of plain water over your paper and then paint it with watercolor. This wet on wet technique will help once you sprinkle the salt because it gives more moisture for the salt to absorb.
STEP 3: Sprinkle Salt
While the paint is still wet, generously sprinkle salt onto the painted areas. You’ll notice that the salt will start to absorb the paint and make it move the paint.
STEP 4: Watch the Magic
Allow the paint to dry completely, and as it dries, you’ll see the salt crystals creating stunning textures and patterns. The salt will leave behind interesting marks and create a beautiful contrast.
STEP 5: Clear the Salt
Once this is completely dry, brush off all of the salt to reveal the pattern in the paint. I love to use this process as a background for an art project because it kind of looks like raindrops or snowflakes.
The Science Lesson
Salt painting works because salt is hygroscopic, meaning it attracts water molecules. When you apply salt to wet watercolor or liquid paint, the water is drawn toward the salt, causing the paint to spread and form a crystalline pattern as the water evaporates. This results in the unique textures and visual effects that make salt art so distinctive.
When the salt soaks up the water, the color in the paint is pulled away from the areas surrounding the salt. This leaves behind lighter areas and creating an eye-catching contrast. The effect is magnified when the salt is applied to areas with more water or paint, allowing the crystals to form intricate patterns as the paint dries.
Once this is completely dry I had the kids make a rainbow and pot of gold to glue on top to celebrate St. Patrick’s Day!
Salt Art Project #2: Salt , Paint and Capillary Action
What do I need?
White School Glue
Salt (I like coarse salt for this as it gives a more visual effect for the kids to observe)
Watercolor paints
Water
Paper
What do I do?
STEP 1: Create a Design
Use your school glue to draw patterns or lines or a drawing on a piece of paper. For littler kids you could have an outline that they can trace with the glue. It’s a great opportunity for some fine motor practice.
STEP 2: Apply Salt
While the glue is still wet, sprinkle salt over the entire design. Make sure it fully coats all of the glue – then shake off any excess.
STEP 3: Allow to Dry
Let the glue and salt mixture dry completely.
STEP 4: Add the Color
Once everything is dry, use watercolor paints and touch the paintbrush to the salt and watch the magic. The paint will follow the path of the salt and not bleed onto the surrounding paper.
Try adding colors near each other and watch the colors blend. This is especially fun when teaching things like yellow and blue make green!
The Science Lesson
There are a couple of things at play here, first is absorption. As we observed in the last project salt is hygroscopic, so it absorbs the paint and water as you touch it with the paintbrush. When watercolor paint is applied, the salt absorbs the liquid.
The second scientific concept we see in action is capillary action. This is where liquid is drawn through tiny spaces between the crystals. As the paint is being absorbed into the salt the excess quickly travels along the line you created with the glue and the salt.
Can we save salt artwork?
By nature salt art is pretty delicate. You can spray it with a thin layer of clear acrylic spray to protect the painting. This will help prevent the salt from coming loose or the paint from fading and humidity.
Extension Activities
Why not power up your Salt Painting projects by making Rainbow Salt Circuits.
Or for extra fun, try Glow Salt Circuits.
These unique art projects using salt and watercolor paints are a perfect balance of art and science. Have fun creating and learning with these STEAM Artworks!