Sébastien Léger's path to venture capital began with nearly two decades at McKinsey, advising on cleantech and building decarbonization scenarios. Around 2020, driven by curiosity about the "next 40%" of technologies not yet at economic parity, he shifted focus toward startups. This exploration led to the co-founding of Slate Venture Capital, alongside two seasoned entrepreneurs and another investor, with a mission to fund and support the next generation of climate innovators.

From clothing to electronics, materials are everywhere—and they’re central to climate challenges. Léger sees advanced materials as pivotal in reducing emissions, increasing circularity, and enabling innovation in key sectors like batteries, wind turbines, and construction. Slate’s fund targets startups that help reduce, replace, or repair environmental impact, with materials playing a critical role across all three.

Slate focuses on Series A and B investments, writing checks between €4–15M and typically taking a 10% stake. Beyond capital, they offer strategic support through a unique network called the Collective Brain—a group of 80–100 experts in industrial scaling, manufacturing, and supply chains. Their investment decisions are based on:

• Climate impact: CO₂ and resource reduction potential.
• Commercial traction: Real (not R&D-subsidized) revenues and customer validation.
• Exit potential: Clear pathways to scale and acquisition.
• Team strength: Experienced founders solving real, validated problems.

Europe is home to around 2,000 climate startups, and Slate accesses them through a mix of inbound outreach, referrals, and direct participation in events like JEC World. Léger stresses the importance of long-term visibility, often engaging with startups well before they’re ready for investment.

While terms like “circularity” and “sustainability” are widely used, Léger emphasizes the need for substance over slogans. He encourages founders to frame their value proposition not just around technology, but around tangible customer and environmental impact—highlighting how their solution improves resilience, reduces waste, or supports biodiversity.

One of the key takeaways for startup founders? Focus on the problem, not the product. Léger advises against diving deep into technical details like "the best membrane or algorithm." Instead, founders should clearly articulate the problem they solve, the measurable impact they create, and their path to scale. Climate VCs want to hear about outcomes, not just engineering.

Regulation can accelerate climate innovation—but it’s not always reliable. Léger notes that while government support (especially in Europe) has driven demand in sectors like solar and wind, startups should aim to create business models that are sustainable with or without policy tailwinds.

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Revolutionizing Sustainability in Deep Tech: Ben Saada of FAIRMAT

In this episode of the Selected podcast, host Ben Costantini interviews Ben Saada, the founder and CEO of FAIRMAT, live from JEC World 2025.

Ben Saada, a pioneer in sustainable materials and deep tech, discusses his journey from inventing the world's lightest aircraft seat to leading FAIRMAT, a startup focused on recycling carbon fiber composites. Saada explains the challenges of recycling advanced materials, his company's innovative mechanical processes, and the importance of creating sustainable and economically viable solutions. He also talks about raising funds, the significance of being a certified B Corp, and his vision for the future of FAIRMAT.

Tune in to learn more about material innovation and sustainability in the tech industry.

00:00 Introduction to the Selected Podcast

00:30 Meet Ben Saada, Founder of FAIRMAT

01:33 Journey Before FAIRMAT

02:46 The Birth of FAIRMAT

04:59 Challenges and Innovations in Recycling Carbon Fiber

05:58 FAIRMAT's Unique Recycling Process

08:34 Growth and Funding of FAIRMAT

12:14 FAIRMAT's Market and Applications

14:05 Sustainability and B Corp Certification

16:28 Global Presence and Future Vision

20:42 FAIRMAT at JEC World 2025

21:28 Conclusion and Farewell

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Julija’s journey into PR wasn’t intentional—she originally planned to become an investigative journalist. A chance conversation with a top journalist led her to explore public relations, a field she knew little about at the time. This unexpected pivot eventually shaped her career, proving that seizing opportunities and networking can lead to new and exciting paths.

Unlike large corporations, startups don’t have an established reputation to manage—they need to build it from the ground up. This requires a different PR strategy, one focused on storytelling and visibility. Julija realized there was a gap in the market for PR agencies that understood startups' unique challenges, which led her to launch Black Unicorn PR. Her agency helps founders navigate media relations, positioning them in top-tier publications.

Not all PR agencies are the right fit for startups. Julija emphasizes that founders should look for agencies that manage expectations realistically and prioritize long-term brand building over quick media hits. A good PR agency will be honest about what’s achievable and won’t promise instant results. Chemistry between the founder and the agency is also key—without trust, effective collaboration is impossible.

With AI tools becoming more common, many feared that PR professionals would be replaced. However, Julija believes AI can enhance productivity but can’t replace human creativity and relationship-building. While AI can help with grammar checks and basic content generation, PR remains a deeply human-driven industry, relying on authentic storytelling and journalist connections.

Julija’s career highlights the importance of networking—not just for sales, but for long-term opportunities. She advises founders to attend industry events with an open mindset, rather than a transactional approach. Building relationships naturally, rather than aggressively pitching, often leads to valuable connections that can pay off years down the line.

PR is a long game, and startups that approach it strategically—by focusing on storytelling, authenticity, and the right partnerships—can build a strong reputation that supports their growth.

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