Indigo is a beautiful deep blue color that has been used as a dye for centuries. When combined with watercolor paints, indigo can produce rich, vibrant blue hues perfect for painting night skies, oceans, or any subject where you want to include a pop of blue. Making your own indigo watercolor paint is a fun DIY project for any watercolor artist looking to expand their palette.
The main ingredient needed to make indigo watercolor is indigo dye powder. This can be purchased from arts and crafts stores, specialty dye suppliers, or online. Once you have the dye, the process simply involves mixing it with the binder gum Arabic (also called gum acacia) and some water. Gum Arabic helps the pigment particles dispersed in the water bind to the paper. With a few simple tools and materials, you’ll be able to whip up this gorgeous blue for your next watercolor project.
In this comprehensive guide, we’ll cover everything you need to know about making your own indigo watercolor paint from scratch including:
– The history and background of indigo as a dye
– An overview of the chemistry behind indigo
– Step-by-step instructions for making indigo watercolor
– Tips for using your homemade indigo paint
– How to care for and store indigo watercolor
Read on to learn all about the process of turning indigo powder into a vibrant handmade watercolor paint.
A Brief History of Indigo Dye
To understand indigo watercolor, it helps to first learn about the fascinating history of indigo dye. Indigo has been used as a blue textile dye for over 6,000 years in many cultures worldwide including Asia, Egypt, and Central and South America.
The main natural source of indigo dye comes from certain species of plants in the genus Indigofera, which are native to tropical and subtropical regions. The most common species used for dye production include Indigofera tinctoria (also called true indigo) and Indigofera arrecta.
To create the blue indigo dye, leaves from the indigo plants are soaked and fermented in water. This long fermentation process causes indigo to convert from its colorless form to the familiar blue hue. Fabric or yarns are then dipped in the indigo vats repeatedly to build up the vibrant blue color.
Indigo played an especially important role in the textile traditions of Asia and India. The vivid blue and white fabrics traditionally worn by many people in India were colored with natural indigo dyes. Japan also has a long history of using indigo dye, called ai, to color kimonos and other textiles.
In North America, native species like Indigofera caroliniana were used to produce blues and blacks among indigenous tribes. During the colonial period, indigo became a major cash crop in the American southeast where it was grown in plantations for export back to Europe.
Later on, chemists discovered how to synthetically create the indigo pigment. This allowed indigo dye production to shift away from relying solely on plants. Today, most indigo dye used for fabric and art pigments is synthetic.
The Chemistry of Indigo
Now that we’ve covered some background, let’s discuss the chemistry behind what gives indigo its distinct blue color.
The chemical compound that forms the basis of indigo dye is called indigotin. Indigotin is insoluble in water meaning it does not dissolve. In its solid indigotin state, the molecule actually appears yellowish.
So how does indigotin shift to become blue? The color change occurs due to a chemical reaction involving reduction and oxidation.
When indigotin is exposed to a strong reducing agent, it loses oxygen molecules and gains hydrogen molecules. This reduced, leuco form of indigotin is soluble and appears yellow-green.
But as soon as the leuco indigotin is re-exposed to oxygen, such as when cloth dyed yellow-green is removed from the vat and dried in air, it quickly oxidizes back to insoluble, blue indigotin.
This fascinating color change between the oxidized, blue indigotin form and reduced, yellow-green leuco indigotin form is the basis for how indigo dyes fabrics and paints such a rich blue. Understanding the principles of reduction and oxidation reactions will help you better control the dyeing process when making indigo watercolor.
Ingredients and Materials Needed
Indigo watercolor paint contains just two main ingredients – indigo pigment powder and gum Arabic binder. Here is an overview of these two key components and the materials you’ll need to make the paint:
Indigo Pigment Powder
This is the colorant that will provide the vibrant blue shade. You can purchase indigo dye powder from art stores, specialty suppliers, or online. Make sure you get an industrial grade powder that is intended for paint making rather than lower quality textile dye.
Aim for a powder that contains at least 60% high purity indigotin. It should appear as a fine, dark blue powder. Synthetic indigo powder works just as well as natural indigo for watercolors.
Gum Arabic Binder
Also called gum acacia, this is the adhesive binder that will help the indigo pigment adhere to the paper once the paint is applied. Gum Arabic is a natural polymer obtained from the sap of acacia trees.
It is soluble in water and dries to form a clear film that attaches the pigment to the paper surface. You can buy gum Arabic as flakes, granules, powder, or liquid. Powdered gum Arabic is the easiest form to find from art supply shops or online.
Additional Materials:
– Distilled water – Using distilled or deionized water is best since tap water may contain minerals that interfere with the dye
– Glass jars or metal tins – for storing the finished paint
– Spoons, small bowls, and measuring tools – for mixing up the paint
– Pipettes (optional) – for adding water dropwise till you get the ideal consistency
– Coffee filters or paint strainers – for straining out any undispersed pigment chunks before storing
Step-by-Step Instructions
Once you have the main ingredients and materials, you’re ready to begin making the indigo watercolor paint. Follow these step-by-step instructions:
Step 1: Measure out the indigo powder
You’ll want to use about 1 teaspoon of indigo pigment per 1 fluid ounce of paint you want to make. So for 4 ounces of paint (about 120 ml), use 4 teaspoons of indigo powder.
Step 2: Measure out the gum Arabic binder
Use approximately 1 teaspoon of gum Arabic powder per 1 teaspoon of indigo pigment.
Step 3: Mix the indigo and gum Arabic
Add both the powdered pigment and binder to a glass or ceramic bowl or jar. Mix them together thoroughly using a spoon or small whisk.
Step 4: Gradually add distilled water
Start by adding just a few drops of distilled water and mixing to form a thick paste. Then slowly add more water a few drops at a time, continuing to mix thoroughly.
Stop adding water when the mixture reaches a nice fluid watercolor consistency. The completed paint should flow smoothly and be able to stick to the brush bristles.
Step 5: Strain the paint
Pour the paint through a coffee filter, paint strainer, or fine mesh sieve to catch any remaining clumps or impurities.
Step 6: Transfer to storage containers
Pour the strained paint into glass jars or metal tins and seal tightly. Label your containers clearly.
Step 7: Let sit overnight
Allow the paint to sit for 6-12 hours before using so the gum Arabic can fully dissolve in the water.
And that’s it – you now have beautiful, vibrant indigo watercolor paint ready for all your artistic creations!
Tips for Using Indigo Watercolor
Here are some helpful tips to get the most out of your homemade indigo paint:
– Mix up fresh paint in smaller batches so you always have wet, fluid paint ready for painting. Indigo dries quickly in pans.
– Stir or shake the paint before each use to redistribute the pigment particles.
– Since indigo sits on the surface, you can layer it lightly over other colors to produce bright turquoise or teal shades.
– Dip your brush in clean water first before picking up paint for vibrant color. Indigo dries paler.
– Try dropping clear water into wet indigo washes for a tie-dye marbling effect.
– Mix indigo with yellow paints like cadmium yellow to make beautiful greens.
– Sketch out your subject first in pencil. Indigo can stain and seep into paper.
– Allow layers to fully dry between applications to prevent unwanted blending.
Caring for Indigo Watercolor Paint
Like other watercolor paints, indigo pigments do have the potential to settle and separate over time. Follow these tips to keep your indigo paints in optimal condition:
– Always remix paint thoroughly before use if it’s been sitting awhile.
– Store indigo paints in airtight containers away from excess heat or moisture.
– Adding a few copper pennies to the jar may help prevent mold from forming.
– Pour off and discard any clear supernatant water that accumulates at the top.
– If paint starts drying out, add more gum Arabic binder rather than just water.
– Avoid freezing or extreme temperature fluctuations which can impact stability.
With proper care, your homemade indigo watercolor should remain usable for many painting sessions before you need to mix up a fresh batch.
Frequently Asked Questions
Is it safe to make my own watercolor paints?
Yes, making your own watercolor paint from ingredients like indigo powder and gum Arabic is perfectly safe. However, take precautions like wearing a dust mask when initially handling dry pigment powders which can be inhaled. Make sure to use non-toxic artist grade pigments from a reputable source.
How long does homemade indigo watercolor last?
The shelf life depends on storage conditions. If kept in an airtight container and stored in a cool, dry place away from direct light, indigo watercolor paint can remain usable for 1-2 years. Avoid letting homemade paints freeze or overheat.
Why is my indigo paint separating into layers?
This is caused by the pigment settling or coagulating. Try remixing thoroughly and adding a small amount of gum Arabic binder if needed to get the paint back to a smooth consistency. Storing paints upside down can also help prevent settling.
Can I premix large batches of indigo watercolor?
It’s best to mix indigo watercolor in smaller quantities that you can use up within a few months. Larger amounts may start drying up or deteriorating in quality if stored for very long periods.
What paper is best to use with indigo paints?
Indigo performs beautifully on any 100% cotton watercolor paper including cold press, hot press, or rough. The texture of cold press paper helps the indigo pigments grab onto the pores.
