How to Clean Natural Pigments

In ancient civilizations, buildings were painted on wood and stone. Everything was covered in color. Artisans documented their environment, cultural traditions and values through art. They sourced their colors from living matter in the ecosystem, such as plants, clay, stones and shells. Nature provided all of the materials they needed to work with. 

In modern times, it’s beneficial for us to make art using an Earth-based sustainable color palette with materials that are easily accessible and ethically sourced. Most commercial paints in mainstream art supply stores are derived from earthen clays and soils, like Burnt Umber and Yellow Ochre, which are common oil paints that are used by professional painters. However, even though the ingredients for these paints come from natural sources, they often contain chemicals that are harmful for the environment and our health.

Pigments are the heart of paint. Many pigments are clay-based. They range in color from the darkest black to bright red to creamy white. You can find a variety of colors in different places like roadside construction sites in urban cities, mountainous hillsides, beaches and riverbeds. 

When we harvest clay and stone from our local environment for painting, it’s important to wash them first to remove extra dirt and debris. 

How to clean natural pigments:

For this activity, you will need the following materials:

• pigment
• glass jar with lid
• coffee filters
• mortar and pestle (optional)

Depending on how much paint you want to make, you can use as many jars as you’d like. For this activity, I’m using 3 jars that I recycled from tomato sauce. Fill your jar about ⅓ to ½ full with clay. It’s okay if there are clumps. You don’t need to break it down into a fine powder until after it’s been cleaned. The water will help break it down anyways. 

I harvested this beautiful red clay from a local construction site in downtown Tallahassee, Florida. The native soil here is abundant with red clay — and it’s perfect for making art! Natural pigments sourced from stone in urban areas reflect the surrounding ecology of the road and the colorful secrets that are hidden beneath concrete. If you happen to spot colored stones or soils while going for a walk, a hike in nature or driving around, take advantage of the moment and bring some stones home with you. 

After the jars are filled with clay to your liking (no more than halfway), soak them with fresh water and pour up to the top. I’m using tap water. You can also use spring water, purified water or rainwater.

Label the jars with the type of pigment, the location where it was sourced, and today’s date. Then place the jars in a spot where they won’t be disturbed. Over the next 1-2 days, you’ll notice the water has transformed from being clay sludge. You’ll see it separated and became more clear and the clay settled at the bottom like sediment. This is the same process that occurs in lakes, rivers and oceans. You just made your own simulation of an ocean sediment!

After 1-2 days, pour off the water on top of the sediment. Observe the appearance of the remaining clay. If you want, you can end your cleaning process here. 

If it looks like the clay could benefit from more washing, then repeat this step by adding more water and letting it sit for another day or so. 

On the final day, pour out all the water from the jar. Now it’s time for your clay to dry so it can be used as a paint pigment.

For the drying process, you will need coffee filters. I use 2 filters at a time. Make sure to put them on a surface that can get a little wet or messy because the remaining water in the clay will soak through the filter and drip out the bottom. 

Scoop the clay onto the filter and place it somewhere that has good airflow. It could be outdoors or indoors. When it dries, it becomes cakey and crumbly. This is when you can grind it into a fine powder with your mortar and pestle. 

And now, you have a cleaned pigment that’s ready for painting!