A conversation with Jeff Forrest of Stackabl Objects and Sophie Pennetier of Digne
The Upcycle: A GFDA Q&A
Two entrepreneurs. Two very different materials. One shared conviction: the waste problem is really a design problem — and design is how you solve it.
Jeff Forrest is the founder of Stackabl, a design-driven manufacturing platform that intercepts post-industrial textile offcuts — wool, 60% recycled PET, cork, stone — and turns them into furniture and lighting. His design studio, STACKLAB, has been incubating these ideas for years; Stackabl is where the system gets to scale.
Sophie Pennetier is the founder of Digne, a materials infrastructure company focused on a different kind of overlooked waste stream: architectural glass. Specifically, the coated, sometimes tempered, high-performance glazing that gets pulled off buildings during renovation and demolition — and almost always ends up in landfill, because the industry has never built a system to catch it.
Jeff has spent the past several years building Stackabl. Sophie is two years into her entrepreneurial journey. The Upcycle sat down with both founders to talk about the businesses they’re building, the obstacles they’ve faced, and why, despite coming from different corners of the industry, they often find themselves making the same case for change.
Pictured chair: ‘Raki’ designed by Alexandra Champalimaud. Lounge: ‘Madame’ designed by Jamie Drake and Caleb Anderson. Photos by Sean McBride for Maison Gerard
Let’s start with the origin story. What made the problem impossible to unsee?
Jeff: It wasn’t a single moment — it was a pattern. Through STACKLAB, we were constantly working with manufacturers and fabricators, and you start to see the same condition everywhere. Not waste in the traditional sense, but systematic overproduction. Perfectly usable material being discarded because it falls outside a spec, a run, or a schedule. At a certain point, you realize this isn’t a flaw. It’s how the system is designed to function.
Sophie: For me it was cumulative too, but with a more specific trigger. In my work in commercial façades, I kept seeing large volumes of high-quality glass removed during demolition and sent to landfill. Not because reuse was technically impossible, but because there was no system to support it. At some point it stopped looking like waste and started looking like a market failure. Digne came out of two ideas that converged around the same time. One was almost philosophical — I had witnessed what I can only call undignified moments throughout my career, where value was systematically discarded. The other was systemic. The name came first, actually. Over ten years ago. As the company took shape, it only made more sense.
Your materials both have strong personalities. How has that shaped your design process?
Jeff: Completely. When you start with remnant material, you lose control quickly. Felt varies in density and color. Edges aren’t perfect. Early on, we tried to force these materials into conventional design frameworks — which either leads to over-processing or compromised results. The shift was moving from designing objects to designing systems. We rely on modular geometries and rules that allow variation without losing coherence. The goal isn’t to eliminate inconsistency; it’s to structure it.
Sophie: Glass defines the rules. It carries coatings, internal stresses, and an embodied fabrication process that directly affect how it can be reused — so design cannot be separated from material behavior. This shifts the entire approach from form-driven to process-driven. Some of our defining characteristics, like color variation, come directly from how the material behaves under heat. Instead of removing that variability, we integrate it into the product. Both the material and the market shape the parameters of the business.
Digne makes its products from glass recovered from buildings, sorted and melted into large plates.
When you describe what you do to someone at a dinner party, what do you lead with?
Jeff: Design. If you lead with sustainability, people assume compromise. If you lead with design, you’re talking about quality, intent, and desirability. The sustainability is embedded in how the system works — starting with waste, minimizing intervention, designing for disassembly. It’s not something we position as a separate layer.
Sophie: Same instinct. If you start with sustainability, people assume compromise. If you start with design and performance, you establish value first. Once that’s clear, circularity becomes a differentiator. We unnecessarily lose people if we dive into supply chain without a warm-up — it introduces complexity. But that’s part of building a new category. You’re not just offering a product; you’re introducing a different system.
What did you underestimate?
Jeff: How difficult it is to build a system around inconsistency. Traditional supply chains rely on predictability. We’re working against that. Inventory is dynamic, material inputs shift constantly. I also underestimated how much translation is required — across customers, partners, fabricators. Everyone needs to understand a different way of thinking about material and value, and that takes time.
Sophie: The absence of infrastructure. The industry is optimized for linear flow: materials are specified, installed, and discarded efficiently. Reuse requires coordination across demolition, logistics, processing, and manufacturing — none of which are aligned by default. The challenge isn’t just technical; it’s aligning incentives across stakeholders. I also underestimated how important it is to control key parts of the value chain early. Without that, it’s very difficult to move from experimentation to repeatability.
Select fixtures from Stackabl Form 58 Lighting collection
We’ll play the cynic for a moment: Is design-forward upcycling just a feel-good story for the design industry while the real waste problem goes unsolved at scale?
Jeff: It can be, if it stays small. If it’s limited to one-offs or small-batch production, it doesn’t meaningfully impact waste streams. But we need to be realistic about where we are. The materials and technologies that could fundamentally change the waste landscape are still a long way from broad adoption. In the meantime, there is a constant flow of material — much of it petro-based — heading toward landfill. Systems like Stackabl can play a meaningful role in managing that reality now. The key is staying grounded in human behavior: don’t alienate the client, motivate them. Deliver something that is well designed, priced correctly, easy to use, and performs. If you do that, and it diverts material from landfill in the process, the system is working.
Sophie: It’s a valid critique. Design-led upcycling can remain at the level of small-scale, high-margin products without addressing the broader waste problem. Our approach is to use design as a market entry point, not as the end goal. Design creates demand and establishes value. Scaling requires infrastructure, standardization, and integration into existing systems. The objective is to build something that can operate at real scale.
Ten years out: does this category get pulled forward by consumer demand, or does it need policy and regulation to push it?
Jeff: In practice, it starts with policy and large design firms establishing baseline criteria. But the real opportunity is shaped on the supply side. Manufacturers need to lead by showing what’s actually possible — building partnerships, developing new systems, presenting viable options that go beyond minimum standards. Over time, those supply-side innovations inform both policy and specification, and that’s how broader adoption happens.
Sophie: Market forces alone aren’t sufficient. Virgin material supply chains are optimized, and environmental costs are not fully priced in — that creates a structural disadvantage for reuse. Regulation will play a role: deconstruction requirements, embodied carbon limits, procurement standards. But policy only works if viable solutions exist. Products still need to perform, scale, and compete. Progress depends on both. Policy creates pressure; industry builds the response.
What would you say to your younger self, or to other sustainability-minded entrepreneurs starting out?
Jeff: If you’re ambitious and you have a novel idea, don’t be afraid to bring in strategic partners early. We tried to build very organically in the beginning. Without advisors, you end up learning everything the hard way. To move quickly and have impact, you need both financial capital and knowledge capital.
Sophie: Focus earlier on the business model. It’s easy to spend time solving technical problems without validating how they translate into a repeatable business. Prioritize supply, demand, and revenue early. And be disciplined about partnerships and intellectual property — in emerging spaces, the value of what you’re building isn’t always immediately recognized. Structure matters from the beginning.
Both Jeff and Sophie are building in the space where design, materials science, and supply chain logistics converge — and where the traditional rules about how things are made don’t quite apply. They’re not starting from a clean spec. They’re starting from what already exists, and asking what it can become.
That, it turns out, is a harder question than it sounds. And a more interesting one.
Jeff Forrest is the founder of Stackabl and STACKLAB. Sophie Pennetier is the founder of Digne, based in Los Angeles. Both are members of the Good Future Design Alliance. Know a candidate for the Upcycle? Get in touch: [email protected]
