Katsuyoshi Inokuma paints a stunning, eye-opening blue. Known as "Inokuma Blue," this ultramarine is the result of a complex process and relentless trial and error.

However, looking back at art history, blue was once an extremely rare and difficult color to obtain in the world of painting.

Why have people been so drawn to blue, and how have they incorporated it into their paintings? Knowing this history offers a new and interesting perspective when viewing Inokuma's work.

Blue is Rare Even in Nature

When we hear the word "blue," we tend to think of the color of the sky or the sea. However, in the natural world, blue colorants themselves are actually very scarce. The blue of the sky is due to light scattering in the atmosphere, and the blue of the sea is also caused by the reflection of light. Both are in reality transparent and do not possess blue pigment.

Furthermore, the appearance of blue in the history of painting came late. The cave paintings of Altamira and Lascaux, believed to have been created tens of thousands of years ago, exclusively used red, yellow, black, and white derived from earth and charcoal. The color blue was almost never seen.

The "Oldest Artificial Pigment" Born in Ancient Egypt

Blue pigment first appeared in history around 1500 BC (about 3,500 years ago) in ancient Egypt. In Egyptian culture, blue was a symbol of the heavens, water, and the life-giving Nile River, revered as the color of life.

At that time, a technique was developed to vividly color the lids of royal tombs and murals. It involved mixing copper-containing minerals (such as malachite) with quartz and lime and firing them at high temperatures. The "Egyptian blue" created this way was the first artificial pigment to appear in human history.

Modern blue pigment in Katsuyoshi Inokuma's atelier, 2023

A Natural Blue Considered Equal to Gold

On the other hand, blue made from natural pigments was difficult to acquire due to the rarity of its raw materials and the complexity of the refining process. Among these, the pigment made from the natural stone lapis lazuli was a supreme luxury item, traded at a price nearly equal to that of gold.

This was because the main mining area for lapis lazuli was in the mountainous region of Afghanistan in the Middle East, a land far distant from Europe. The ore traveled along the Silk Road and crossed the Mediterranean Sea to reach Europe. For this reason, this vibrant blue came to be called "Ultramarine," from the Italian words meaning "from beyond the sea."

Lapis lazuli was already valuable as a gemstone, and its processing was also fraught with difficulty. The stone is brittle and easily crushed, but grinding it too finely turns it into a dull, grayish powder. Moreover, it loses its color when mixed with oil, which meant that an extremely high level of skill was required for the refining process to extract only the blue component.

The combination of the rarity of the raw stone transported from across the sea and the high technical skill required for its refinement made ultramarine blue exceptionally expensive, and it became a symbol of nobility and power. Consequently, in medieval Europe, this blue was a special paint that could only be used for significant motifs, such as the robes of the Virgin Mary.

From the Virgin's Color to the Common People: How Vermeer Changed Ultramarine

Johannes Vermeer, The Milkmaid, 1660, oil on canvas, 45.5 × 41.0 cm, Rijksmuseum, Amsterdam (Creative Commons / CC0)

One artist captivated by this ultramarine blue was the 17th-century Dutch painter Johannes Vermeer. Supported by his wealthy family's fortune, income from his family business, and the assistance of patrons, he was able to use ultramarine blue extensively. He also used it in ways that broke from convention; whereas it had previously been reserved for noble subjects like the Virgin Mary's robes, Vermeer applied it to the clothing of common people and even used it as an underpainting. Vermeer is known as a painter who depicted light, and he used blue and yellow as the colors to represent that light.

In the summer of 2026, Vermeer's "Girl with a Pearl Earring" can be seen at the Nakanoshima Museum of Art in Osaka, where the blue turban is used in an impressively striking manner.

The "Blue of Plants": Part of Life, but Not of Painting

Meanwhile, a familiar blue in Japan was ai (indigo), which was derived from plants.

Although it was popular in practices like aizome (indigo dyeing) for kimonos, plant-based blues were prone to fading in sunlight and washing away with water. It was quite difficult to make them adhere to washi paper or silk as a paint. There was also a mineral pigment called gunjō, made from crushed azurite, but it was expensive and its particles were coarse, making it unsuitable for popular ukiyo-e prints .

This situation was transformed by the importation of the artificial pigment bero-ai (Prussian blue) during the late Edo period. The arrival of the inexpensive and fine-grained Prussian blue enabled artists like Hokusai to depict vibrant gradations of sky and sea in ukiyo-e.

Blue Becomes Freely Usable

In the 19th century, advances in chemistry led to the production of inexpensive blue paints. Once paint became available in portable tubes, blue became an accessible color for everyone.

As blue became freely available, its applications expanded. The Impressionist painters used blue to express the light and atmosphere of landscapes, while Picasso filled his canvases with blue during his "Blue Period" to convey the loneliness and sorrow of his youth. Blue has become a color for expressing an artist's emotions and themes.

Katsuyoshi Inokuma: Exhibition View (First Half)

To Contemporary Art and the "Blue" of Katsuyoshi Inokuma

Today, even elementary school students can use blue paint in their art classes as a matter of course. Blue, along with all other colors, has become a familiar and accessible medium for creation. It can be said that this is precisely why contemporary artists are able to more clearly reflect their own ideas and intended themes in their choice of colors.

The works of Katsuyoshi Inokuma, featured in the currently held exhibition, strongly convey this very allure of blue.

There are several steps to creating his vibrant ultramarine, known as "Inokuma Blue." A base coat of a pink paint called "Luminous Pink" is applied first, and then multiple layers of blue paint are applied over it. Coffee powder is mixed into the blue paint, which further enhances its unique matière, or texture. Furthermore, after layering, the surface is scraped to create a uniform expression. It is this calculated process that gives birth to that deep, captivating appearance.

Katsuyoshi Inokuma in his atelier, creating a work. The pink undercoat is still visible. (Photographed in 2023)

The history of people who sought the color blue and persevered through trial and error to stabilize it as a paint is long. Thinking that Inokuma's blue, right before our eyes, exists on the extension of that timeline makes appreciating his work all the more fascinating.

▼ The late Katsuyoshi Inokuma on his passion for "blue" and the behind-the-scenes of his creative process (Interview from 2023)
A New Frontier for Inokuma Blue | Katsuyoshi Inokuma "Transition" Interview

Deep into the Blue