Outremer

The French word for ultramarine is bleu outremer. The Italian is blu oltremare. Both mean the same thing: blue from beyond the sea. The pigment came from lapis lazuli mined in the mountains of Badakhshan, in what is now Afghanistan, and traveled by caravan across the desert and then by ship across the Mediterranean. It cost more than any other color. It cost more than gold.

The convention developed in medieval Europe to paint the Virgin Mary in ultramarine specifically because of this cost. The most expensive pigment was allocated to holiness. The blue robe signaled: someone paid the maximum for this. The blue was the evidence of the painter's devotion, before it became the symbol of the saint's virtue.

The mines Marco Polo visited in 1271 and called "the finest and most beautiful of blues" were the same mines that had been supplying the color for centuries. The same mountains. The pigment that made the Virgin's robe had been making the eyebrows blue on Tutankhamun's funeral mask fifteen hundred years earlier.

In about 2500 BCE, Egyptian artisans began making the first synthetic pigment — a manufactured blue to replace the imported one. They ground silica, lime, copper, and alkali, heated the mixture to 900 degrees Celsius, and produced Egyptian blue: the first color humans ever made from scratch. Before that, blue meant Afghanistan. After that, it meant a furnace.

Prussian blue was discovered in 1704 by a Berlin paint manufacturer who was trying to make red. He combined iron sulfate with a potassium compound he had obtained from a source that contained dried blood. The result was the first modern synthetic blue — a deep, intense, accidental color made from iron and blood trying to become something else entirely.

In the deep ocean, the creatures who make their own light make it blue-green. Not because blue is beautiful but because blue travels furthest in water — the shorter wavelengths penetrate where red and orange and yellow cannot reach. The bioluminescent creatures have converged on blue because blue goes where other colors don't. Blue is the color of maximum reach in the dark.

The plant Pollia condensata makes the most intense blue in any living tissue without any blue pigment at all — through the spiral arrangement of cellulose microfibers, precisely calibrated to the wavelength of blue light. Structure, not substance. The blue in the marble berry is the arrangement reaching toward the frequency that carries furthest.

Ultramarine, outremer: from beyond the sea. Distance is encoded in the name. Blue has always been what you find at the edge of reach, or what costs the reach to obtain. The sky at the horizon. The deep past visible in deep space. The signal from the bioluminescent creature at 1,000 meters depth. The pigment from the mountains of Afghanistan.

Everything that reaches furthest, at the moment it becomes visible: blue.