Interview with Marcela da Terra, Part 2: Recipes for Reconnection — The Collective Practice of Earth Pigments
Contiuing on from Part 1: Rescuing Memory and Identity Through Soil
By Nina Purton
If sustainability is about systems, Marcela da Terra’s answer is grounded: start with the soil beneath your feet.
Her research simultaneously explores routes for us to reduce our environmental impact when painting our homes and decorating our lives with colour while decentralising knowledge, reviving ancestral practice, and bringing communities together through collective creation. From murals in schools to DIY paint kits, Marcela’s biodesign philosophy begins with what is local, accessible, and alive. She traces a path for design that is sustainable as it is relational, demonstrating the unique potential of soil to build relationships between people and their lands.
Collective Biodesign
Marcela’s processes are deeply entrenched in biodesign — but not in the sterile, futuristic way it’s often presented. Her approach is low-tech, deeply local, and rooted in traditional practices. She sources materials from the land itself, with simple and effective tools, some are tools designed for other activities that she adapts to her work, like a cheese drainer, reflecting an age-old mentality that objects can have multiple functions to those who are willing to observe them. She collaborates with the people who live close to the land.. Sometimes that means harvesting pigments in a community ravine. Other times, it means offering a workshop where residents create murals using materials from their own territory.
For her, sustainability is transdisciplinary by nature. “I think sustainability goes beyond the ordering of disciplines. It penetrates all areas of life,” she explained. “If I speak about earth pigments, for example, I can connect them to everything.”
Her networks reflect that philosophy. Marcela teaches through SENAR Minas, a national programme focused on rural education, and is an active member of Rede Terra Brasil, a network of builders and researchers working with natural materials. She is also part of the collective Mulheres na Bioconstrução (Women in Bioconstruction), and Terra Coletiva — an international group of artists from countries like Brazil and Chile that are using earth pigments to create artworks and revive ancestral knowledge.
Her workshops are intentionally collaborative. Participants take part in every stage of the process: observing the soil, collecting it, preparing it, and painting. “You need to work with others because you’ll be creating together, you’ll be collecting soil together,” she said. “It’s teamwork, the kind of work that requires you to think about others.”
In this model, teaching is not top-down. The pigment becomes a shared experience that restores confidence, memory, and local pride. In many places, it is the first time residents have seen their own soil used in something artistic, something beautiful.
This participatory model challenges the individualism that often dominates both art and science, reminding us that material innovation is inseparable from social connection.
The Practice of Making
During the pandemic, Marcela developed some products to keep her work going. Among her creations is the caixa rupestre — or “rupestrian box” — a DIY kit that contains raw materials and a step-by-step guide for people to create their own paints at home. The kit is both playful and pedagogical. It invites people to interact with the materiality of earth, to mix their own paints, and to reconnect with processes that are usually hidden behind store-bought goods. Like her murals, the box is a tool for autonomy — encouraging people to explore their own surroundings, observe local soils, and discover the colours of their region.
The process of making pigments involves a good deal of curiosity, the kind that requires careful attention. Marcela approaches each new soil sample as an invitation to observe and learn. Whether she’s preparing wall paint or watercolours, the first step is always the same: paying attention to what the earth reveals. “This work with earth pigments, as with any other natural resource that we begin to investigate more deeply, requires us to look, to learn to observe firstly,” she says.
For wall paints, she dries the clay, crushes it, sieves it, then blends it with water. The mixture is adjusted for viscosity by hand, which must be done very carefully and gradually to achieve the right proportions, she assured me. For fixatives, she often uses white PVA glue — a synthetic material, yes, but chosen meticulously. This choice is based on research by civil engineer Fernando Cardoso, who investigated a wide range of natural and synthetic binders to identify an effective, low-impact option that would balance durability, cost, and accessibility. “Even using this synthetic material,” Marcela explained, “the paint has an environmental impact that is infinitely smaller compared to conventional paints.“
She understands this as part of a transition. While she continues to explore fully natural fixatives — such as grude de polvilho (a sticky porridge made from tapioca starch) — her focus remains on what is both accessible and effective. She holds the view that science will evolve, and that we should use what works best in our current context — especially where it gives people autonomy to make healthier paint options that also beautify their homes.
For watercolours, the process is more delicate and demands patience. After sieving the dried clay through a coarse sieve, Marcela passes it again through a finer filter — often a cheese drainer — to help reduce airborne dust. She then grinds the fine particles using a mortar and pestle, refining the texture even further.
Once the dry pigment is ready, it’s blended with a homemade natural binder made from acacia gum, vegetable glycerin, and essential oils. To achieve the right texture, Marcela uses a muller — a flat glass tool — working it against a frosted glass base to smooth the mixture evenly. This step is essential to create a paste with a fine, consistent application quality. “It’s not just mixing — it’s about creating a body for the paint,” she says.
The resulting paint is poured into small ceramic moulds and left to dry gradually, eventually forming solid pastilles that blend functionality and beauty. Their colour and texture reflect the places they came from, their ‘geological’ nature – a word Marcela likes to use to describe her work.
Yet the slowness is essential. It’s in the making — the crushing, the mixing, the waiting — that people start to build intimacy: with the land, with the material, and with others. “Often, when we start to walk, and to look, we dig out a ravine here, another there… people are surprised — ‘wow, here in my region there are so many beautiful things.’”
These pigments do more than coat a wall. They restore a sense of presence, ownership, and belonging. “In many places, this art made with earth pigments by the very community was the first piece of art there,” she said. “It was like an inauguration.” The murals become landmarks — visual declarations that a community is here, that it has a palette, a story, and a voice.
Conclusion — The Soil is Speaking
Marcela da Terra’s work reminds us that biodesign doesn’t need to come out of a lab. It can come from a ravine, a schoolyard, or a community that has interacted with its soil for generations.
Each pigment is a collaboration with place — textured, seasonal, imperfect, and alive. “Each place has its own colour palette,” she said. Even if the tones are similar, “they always vary, and never repeat themselves.”
In a time when sustainability is often marketed as sleek and futuristic, Marcela’s practice brings us back to earth — literally and figuratively. It invites us to move slowly, to look more closely, and to remember that colour, like memory, is carried in the land.
What if the materials of the future are the same ones we’ve walked on for millennia?
About the Author
As a sustainability, innovative materials and well-being writer, Nina Purton is an avid investigator of all things circular. She is set on researching behavioural patterns, pioneering materials and initiatives that are revolutionising the way we produce, consume, and relate to other human beings and the natural environment.
You can find out more about her on her LinkedIn profile and website.