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When humans sought "color," earth paints were the most familiar material and the source of expression. Earth paints have supported the art of all cultures throughout time, from prehistoric times to the present day, including the murals of the Lascaux caves in France.

In this article, we will explain the composition of pigments, which are the source of color, the steps and points to sublimate them into "paints," and even techniques to bring out the individuality of the material.

1. The origin of “color” deciphered from earth pigments

The colors of the earth are more than just visual information. It contains the eternal geological history of the place where it was collected.
In this section, we will delve into the secrets of the robust characteristics and diverse color tones of earth paints from a scientific perspective. We will also explain the differences between synthetic pigments, which are often confused with each other, and suihienogu.

Solidity of earth paints

This material, which has undergone oxidation and weathering processes over many years in nature, is an extremely stable inorganic pigment that is resistant to further chemical changes. 
The biggest feature is its overwhelming "robustness". It has high resistance to fading due to UV rays, as well as changes in humidity and temperature. The fact that cave paintings from tens of thousands of years ago still retain their original colors is a clear testament to the enduring strength of this material.

Colors and Science of the Earth: Ingredients and Characteristics Created by Nature

The color tone of clay paints is determined by the content of iron oxides and manganese oxides in the mined soil, and the balance with the base clay minerals.

The main hues such as red, yellow, and brown are iron oxide, which is a component similar to the "rust" of common iron. When manganese oxide is added here, its black component suppresses the saturation, creating a deep dark brown or blackish brown color. In addition, the hiding power* varies greatly depending on the clay, ranging from opaque to highly transparent, which produces a beautiful effect as a glaze (transparent layer).

Here, we will focus on three major clay paints with different hues: ocher, red earth, and green earth, and compare their compositions and characteristics.

*Concealing power: power to cover the underlying color. When it is high, it is opaque, and when it is low, it is transparent.

Yellow Ochre

Main component: Hydrous iron oxide (goethite/goethite)/clay (*sometimes called limonite/limonite)
Tone: It has a natural warm color range from warm cream color to golden yellow to yellowish brown.
Characteristics: Hiding power is from semi-transparent to semi-opaque. This pigment has medium tinting strength and blends easily with other colors.

Red Ochre

Main component: Iron oxide (hematite/hematite)/clay
Tone:Basically reddish-brown, colors range from strong bengara-like colors to bright vermilion like taisha.
Characteristics: In general, it has a higher hiding power than loess, and hematite with high purity has a particularly strong covering power. It has very strong tinting power, and even a small amount can strongly affect the color tone of the other color mixed.

Green Earth

Main component: Silicate minerals derived from ancient marine sediments (such as celadonite, glauconite, glauconite, etc. *Chlorite, etc. may also be mixed in)
Tone: It ranges from yellow-green to celadon-like sea green to gray-green. It is also attractive that the expressions differ depending on the region of production, such as "Bohemian green soil" and "Itari subgreen soil."
Characteristics: It has modest hiding power and coloring power, and is characterized by a transparent texture. Because of its delicate nature, it has long been valued for undercoating and adding exquisite nuances and tonal changes.

2. Structural comparison with synthetic pigments and suiboshi paints

In order to better understand the characteristics of earth pigments, we will clarify the differences between "synthetic pigments," which have different compositions, and "suiboshi pigments," which have the same shape and manufacturing method.

Comparison with synthetic pigments: Attractiveness of color development and off-taste

Synthetic pigments, developed since the 18th century, are chemically produced and controlled. Its greatest features are extremely low impurities, high color saturation, and strong coloring power.

On the other hand, although natural earthen paints have been refined, they still contain minerals derived from the geological formations and trace amounts of impurities. Scientifically speaking, this impurity can be called a "miscellaneous taste," but it is this impurity that brings to the screen a depth that is difficult to reproduce with synthetic pigments and the calm nuances unique to natural materials.

Choose synthetic pigments for areas that require a vivid accent, and earthen paints for areas where you want to give depth and natural fluctuations to the screen, depending on the intent of each expression.

Two different pigments born from the "Suihi" manufacturing method

"Suihi" originally refers to the process of purifying with water and drying it into a board shape. The generally available "suihi pigments" and "earth colors" follow similar processes, but there is a decisive difference in their color structures.

Although it is crushed to some extent during the production stage, hard plate-like pieces (flakes) and powders of various sizes are mixed in.

Suihi Pigment

It is colored by using an extender pigment such as gofun (oyster shells) as the core (base), and mixing it with pigments and dyes. Therefore, it is characterized by the ability to freely create stable colors, from extremely bright colors to dark tones.

Earth colors

It is made by crushing and refining the soil itself, and is not colored at all. Here lies the true beauty of earth colors, filled with the colors of the materials themselves.

3. The expression of clay paints changes depending on the coloring agent

Paints are made by kneading pigments, which are the base of the color, and a medium, which acts as a binder.
Pigment powder will not stick to the base material such as paper or canvas just by dissolving it in water. "Fixing strength" is created only when each pigment particle is coated (filmed) by mixing it thoroughly with an appropriate color vehicle. Through this process, it functions as a "paint" with beautiful colors and a texture suitable for drawing.

How to choose painting techniques and coloring agents

The hue, texture, and properties of the paint change depending on the color vehicle (medium) used with the pigment.

Earth color expression brought out by color vehicle

acrylic emulsion

How to apply (from top): Thick coating/Standard coating

[Art materials used]

Earth color: Moroccan Taisha
Binders: Acrylic Emulsion
Base material: Bamboo Washi for Watercolor
 

Acrylic emulsion, which dries to form a water-resistant coating, has strong adhesion, and although it is water-based, it can be used on a wide range of base materials, and it firmly fixes even coarse pigments. Because the acrylic resin coats the pigment particles in a way that envelops them, a deep "wet color" is achieved even after drying. By taking advantage of its fresh color luster and quick-drying properties, you can create expressive textures, from smudges and gradations to thick coatings.

Animal Glue

Painting method/technique (from top): Standard painting/tarashikomi/bleeding/blurring

[Art materials used]

Earth color: Moroccan Taisha
Binders: OX glue liquid 20％ concentrated
Base material: Bamboo Washi for Watercolor

Glue has the property of shrinking as the moisture evaporates during the drying process. Therefore, when it dries on the screen, the pigment particles are exposed on the surface, highlighting the matte and rustic texture inherent in earthen paints. Another attractive feature of glue is that it is not covered with a paint film like other color vehicles, so the original colors of earth colors can be expressed beautifully as they are.

4. Make a paint color

Making the pigment finer: Karazuri

Earth colors made using the water-drying method do not mix evenly with the vehicle if they are large particles or hard lumps, causing roughness, uneven color, and poor fixation.
After adding a coloring agent to the pigment, the particles harden and become difficult to crush, so it is necessary to "Karazuri" the pigment in advance to make it into fine particles. By making the particles finer in advance, the efficiency of kneading work will be improved.

We recommend using a mortar, especially when working with hard pigments or large quantities of the same color.

Alternative method if you don't have a mortar

When using a small amount or creating multiple colors at the same time, you can use slightly thicker paper of A4 size or larger and a cylindrical stick. Fold the paper in half, sandwich the pigment in between, and mash it by rolling a thick stick (rolling pin, Pestle, etc.) over the paper.

How to make paints depending on the color vehicle

No matter how you make it, the more carefully you knead it, the more gloss it will have, and the smoother the texture and brighter the colors will be.

The key points in making and blending differ depending on the type of color vehicle used. For more information on making paints and tools, please refer to the article below.

Mixing ratio of pigment and vehicle

The optimal ratio varies depending on the type of pigment (specific gravity and oil absorption), but please use the values below as a guide.

[Watercolor paint/acrylic paint] Pigment 1: Color developer 1
[Oil paint] Pigment 1: Color vehicle 0.5
[Glue] Pigment 1: Color vehicle 0.7-1

How to use a mala and a marble board

Because it grinds the pigment particles and blends them with the vehicle, it is ideal for making paints that require careful mixing, such as oil paints and coarse-grained clay paints.

Paints that can be created: Watercolor paints, acrylic paints, oil paints

Click here for details.

How to make with a palette and a painting knife 

If the pigment has been air-printed in advance, it can be mixed using a paper palette and a painting knife. Paper palettes have a white background that makes it easy to see the colors, and they are also suitable for toning (*It may not be suitable depending on the type of pigment or the amount you make at one time).
This is the easiest method to practice when making small quantities or for those making paint for the first time.

Paints that can be created: Watercolor paints, acrylic paints, oil paints, etc. made with fine-particle pigments

How to knead with your fingers using Animal Glue

This is a traditional technique in which pigments are placed in a dish, etc., animal glue is added, and the mixture is carefully kneaded with the pads of the fingers.

Paints that can be created: Paints for traditional Japanese painting techniques

[Related articles/videos]

Discover Earth colors from around the world at PIGMENT TOKYO

PIGMENT TOKYO has a earth color collection of about 50 colors spanning about 10 countries.
Why not try incorporating the story of the earth that has continued since time immemorial into your work through the process of developing earth colors?

Editor & Writer

Natsuko Shiraishi

Graduated from the Textile Design at Tama Art University. She is an artist who mainly works with original Washi paper and calligraphy.

Favorite matière: Paper, dynamic moves of wood fiber

Graduated from the Textile Design at Tama Art University. She is an artist who mainly works with original Washi paper and calligraphy.

Favorite matière: Paper, dynamic moves of wood fiber

PIGMENT TOKYO

PIGMENT ARTICLES delivers a wide variety of information about art. You’ll find instructions on traditional painting techniques, art materials, and the latest updates on products, workshops, and events.
We invite you to explore our articles for creative inspiration and to deepen your knowledge.

PIGMENT ARTICLES delivers a wide variety of information about art. You’ll find instructions on traditional painting techniques, art materials, and the latest updates on products, workshops, and events.
We invite you to explore our articles for creative inspiration and to deepen your knowledge.