By Beatrice Mwasi – Managing Director, Center for Business Innovation & Training (CBiT)
7th October 2025
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Fashion is hungry for sustainability. It celebrates circular design, experiments with new biomaterials and promotes heritage craft as a marketing tool. Yet one of the most circular, heritage-rich tanning traditions, still alive in parts of southern Africa, rarely appears in these conversations. The practice is called letsoku tanning, and it uses nothing more than clay, water and oil to preserve and color hides in striking shades of red.
“Letsoku is not only technique. It is identity.”
Among the Sotho–Tswana and San peoples, letsoku is more than technique. It is identity. The clay’s vivid color carries ceremonial meaning, appearing in garments, symbols of status and protective cosmetics. Wearing leather tanned with letsoku is not only practical but symbolic, an expression of belonging, history and continuity.
The science behind this craft is remarkable. Letsoku is rich in hydrated iron oxides that slow the natural enzymes which break down hides. In other words, it does chemically what industrial preservatives are designed to do, but with earth itself. Applied to a hide, it preserves, softens and colors in one step. When combined with animal fats or oils, it also provides water resistance. The process requires no external additives, no complex machinery and no imported chemicals. Every step— digging, grinding, mixing, rubbing, softening— is carried out by hand, producing hides that bear the mark of both maker and land.
“This clay preserves, softens, and colors in one step—earth doing the work of chemistry.”
What emerges is leather that is both durable and beautiful. Each piece carries its own red sheen, impossible to standardize but instantly recognizable, linking product to place in a way industrial tanning cannot. This uniqueness is not a flaw, it is a strength. In a market saturated by uniform materials, letsoku offers character, authenticity and a story that resonates with consumers who increasingly value provenance and craft.
None of this diminishes the role of large-scale tanning. Industrial methods ensure the world is supplied with the volumes of leather modern markets demand. They make possible the shoes, bags and upholstery that consumers take for granted. But heritage systems like letsoku expand the sector’s horizons. They demonstrate that leather can also embody cultural meaning, ecological balance and artisanal resilience. The two approaches are not at odds; they are complementary, each showing a different facet of what leather can be.
“Each hide carries its own red sheen, linking product to place in a way industrial tanning cannot.”
Yet this tradition is fragile. Letsoku tanning is slow and tied to specific geology, which limits its spread. Younger generations may see it as outdated. Without recognition and investment, such practices risk being lost and with them an irreplaceable layer of cultural and ecological knowledge. To preserve them requires deliberate effort: training new artisans, encouraging sustainable harvesting of clay and plants and creating space for these leathers in markets that value authenticity and heritage.
The lesson of letsoku is simple but profound. Sustainability is not always about inventing something new. Sometimes it is about respecting what has endured. Fashion’s sustainability debate too often privileges novelty, lab-grown hides, synthetic substitutes and high-tech solutions while overlooking practices that have quietly solved the same problems for centuries. Letsoku reminds us that working with natural systems can be as effective as attempting to reinvent them.
“The two approaches are not at odds; they are complementary, each showing a different facet of what leather can be.”
The leather sector has room for both innovation and inheritance. Chrome and vegetable tanning will continue to meet global demand. But heritage crafts like letsoku offer inspiration and balance. They remind us that leather is not just a material measured in square feet. It is also a relationship between people, land and culture.
“In the red sheen of a letsoku-tanned hide lies not nostalgia but possibility.”
The question is whether fashion will continue to treat such traditions as relics or recognize them as living solutions. In the red sheen of a letsoku-tanned hide lies not nostalgia but possibility, evidence that the future of leather may, quite literally, be rooted in the ground beneath our feet.
What Is Letsoku Tanning?
The Material: Letsoku is a naturally occurring ochre or clay rich in hydrated iron oxides.
The Process: Clay is dug, ground, sometimes heated, then mixed with water or oils. Prepared hides are rubbed or soaked in the mixture and softened by hand as they dry.
The Science: Iron oxides slow down collagen-degrading enzymes, preserving hides while adding a permanent red hue. Mixed with fats, letsoku also improves flexibility and water resistance.
The Culture: Among the Sotho–Tswana and San peoples, the vivid red of letsoku is tied to ceremony, identity, and belonging.
The Value: Letsoku tanning is small-scale, heritage-rich, and environmentally rooted, complementing the industrial methods that supply leather to global markets.