DIY Gouache: A Step-by-Step Guide to Making Your Own Opaque Watercolor Paint

Gouache is an opaque watercolor paint made by mixing pigments with a binding agent, typically gum arabic. The resulting paint is thicker and more opaque than traditional watercolors and is often used for illustrations and other forms of commercial art. Learning how to make gouache at home by mixing pigments with gum arabic and water allows artists to customize their paints for optimal opacity, texture, and color vibrancy, offering greater creative control over their work.

What Is Gouache and Why Make It Yourself?

What makes gouache different from watercolor paint, since both use gum arabic as the binding agent? The opacity of gouache and how it is handled makes it different. Extender pigments such as barite (baryte, British spelling) or the synthetic mineral blanc fixe are added to most pigments to increase the opacity of the paint. Some pigments, such as most earth pigments, do not require extender pigments since they naturally contain extenders, such as chalk or quartz.

Essential Materials for Homemade Gouache Paint

To make gouache paint, you will need the following materials:

• Pigments: You can use any pigments suitable for watercolors, such as natural pigments like yellow ocher and burnt sienna or synthetic pigments like phthalo blue and quinacridone violet.

• Extender Pigments: Barite (baryte) or chalk is used to add opacity and extend the pigments.

• Gum arabic: This is a natural binder that is derived from the sap of the acacia tree.

• Glycerin (preferably from a vegetable source)

• Water (preferably distilled water)

• Borax

• Grinding plate (smooth, flat glass or stone plate)

• Muller (glass or stone muller to grind the paste)

• A palette knife or spatula for mixing the paint

• Mortar and pestle (for grinding pigments if necessary)

• Scale or measuring spoon (for measuring the pigments, gum arabic, and other ingredients)

• Glass or plastic dropper (for adding water to the paint)

• Glass or plastic containers with lids for storing paint.

All of the materials you need above are available from Natural Pigments.

Preparing the Gouache Binding Agent

Prepare the binder for gouache paint. Borax is a preservative that prevents the solution from spoiling. It isn't necessary to store the solution in the refrigerator.

Steps:

1. Add gum arabic powder to water.

2. While stirring, gently warm the solution without exceeding 140°F (60°C) until all the gum dissolves.

3. Prepare the second solution by adding borax to water.

4. Stir gently and warm the solution until the borax dissolves.

5. Add glycerin to the solution.

6. Mix both solutions and store them in a sealed container.

Of course, you can skip this step entirely by purchasing Watercolor Medium from Natural Pigments.

How to Make Gouache Paint

1. Measure out pigment and extender pigment (such as barite or chalk) using a scale or measuring spoon. A good starting ratio is 1 part pigment to 2 parts extender pigment.

2. If the pigments are not finely ground, use a mortar and pestle to grind them to a fine powder.

3. Mix the pigment and extender pigment together in a bowl using a palette knife or spatula until well blended.

4. Place the pigment mixture on the grinding plate in a pile. Slowly add the gouache binding agent, a few drops at a time, mixing until you reach the desired consistency. Gouache paint should be thicker than traditional watercolor but still pourable.

5. Gather the paste, place the muller on top, and grind using back-and-forth or circular motions. Heavy pressure isn’t necessary; the grinding action comes from the muller’s horizontal movement.

6. Once the paint is smooth, transfer it to an airtight container and label it with the color name and date.

7. Let the paint sit overnight to fully integrate the pigments with the binding agent.

8. After resting, your homemade gouache paint is ready to use.

Note: The amount of gouache binding agent depends on the pigments and the desired viscosity. Some organic pigments may require a wetting agent to aid in dispersion.

Common Mistakes and Storage Tips

• Storage Solutions: Store homemade gouache paint in airtight containers and use it within 6–12 months to maintain freshness and vibrant color.

• Common Mistakes: Avoid incorrect pigment-to-binder ratios, using subpar materials, and neglecting proper storage, which can lead to cracking or mold growth.

• Lightfastness Warning: Homemade gouache may not have the same lightfastness properties as commercial gouache paints, which are often formulated for greater stability.

Final Tips for Achieving Professional Results

By making gouache paint at home, you not only control the colors and consistency but also gain valuable insight into the properties of your materials, allowing for more informed and creative artistic decisions. With this guide on how to make gouache, you can create vibrant, high-quality paints tailored to your artistic vision. Just remember to use high-quality materials, measure accurately, and store your paints properly for the best results.

References

“Gouache.” Merriam-Webster, Merriam-Webster, n.d.

“Gouache.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., n.d.

“Making Gouache Paint.” Blick Art Materials, n.d.

“Gum Arabic.” The Metropolitan Museum of Art, n.d.

“Gouache Painting Techniques.” Artists Network, n.d.