Indigo is an exemplary substance in world ecology and the formation of the modern commodity market. The biography of the plant (Indigofera tinctoria), from which the eponymous vivid blue textile dye is produced, is intimately intertwined with a global history of agrarian reform, logistics, political economy, and colonisation. During the late sixteenth and early seventeenth centuries, several European countries—including France, Germany, and Britain—prohibited indigo imports to protect local industries based around the native woad plant (Isatis tinctoria). Indigo’s eventual dominance as a transatlantic cash crop in the seventeenth century grew as the French in Saint-Domingue, the British in Jamaica, and the Dutch in Java cheapened a highly labor-intensive process through the use of enslaved people. South Carolina eventually dominated the trade from the 1740s to the 1850s, an era that had a dramatic and devastating effect on the scale of the transatlantic slave trade.

A work in Kapwani Kiwanga’s exhibition “Changing States”, which just opened at the Fundació Joan Miró in Barcelona, brings to mind the piece “Untitled (Blue)” (2017) by Zurich-based duo Christina Hemauer and Roman Keller. This 4.5-meter-wide canvas of dyed and bleached denim was produced for the group exhibition “4.543 billion: The Matter of Matter”, curated by Latitudes at the Capc Musée d'art contemporain de Bordeaux. Kiwanga’s new tapestry, “Shift in Hue” (2026), similarly traces raw materials linked to the histories of global trade, specifically the transition from European woad and linen to the indigo and cotton grown and harvested through the labor of enslaved people.

Hemauer/Keller’s work, now in the Capc collections, weaves together the histories of botany, capital, coal, and colour. It juxtaposes an emblematic invention of modern art—the large-scale abstract painting—with blue denim, the iconic cloth of American frontier mythology. The artists’ “painting” is comprised of two elements of stretched textile accompanied by an audio narration. One band is cotton that has been incrementally hand-dyed using natural indigo to produce a ombré effect, while the other is commercial denim that has been progressively bleached.

Both Kiwanga’s and Hemauer/Keller’s works relate to indigo as one of the many commodities that would have passed through the Entrepôt Lainé warehouse for colonial produce—the building that now houses the Capc—during the 19th century. This connection was also explored in Kiwanga’s 2023 installation “Retenue”, which filled the Capc nave with over 50 kilometres of indigo-dyed rope.

The narration in Hemauer/Keller’s work touches on how the invention of artificial dyes synthesised from coal tar at the end of the 1800s led to a drastic fall in demand for natural plant dyes; by 1914, indigo production in India had almost entirely stopped. Chemists had discovered a more “reliable” version of nature, and the German and Swiss family firms that transformed into global companies through synthetic dyes—including Geigy, Bayer, Hoechst, and BASF—would come to dominate the chemical industry for the next century and a half.