Copenhagen-based Bundle Studio was formed to explore the use of bio-based materials in furniture. "We believe designers must redefine material use for sustainability," write founders Jón Hinrik Höskuldsson and Kirstine Nørgaard Sejersen, "and we aim to create functional, aesthetically pleasing products that push the boundaries of sustainable materials and inspire industry change."

Messing around with materials in the studio ultimately led to their Bundle chair:

"Through extensive experimentation, we developed a stackable, lightweight mono-material chair by thermo-pressing flax fibres and PLA into rigid shells. The chair weighs 2.5 kg, with about half of that weight being bio-based plastic."

"The project emphasizes material-driven design guided by creativity and curiosity, using biobased composites to challenge traditional plastic furniture construction. By splitting the chair into smaller components, we improved material efficiency and introduced a craft-like quality uncommon in plastic furniture. The incorporation of flax fibres into a PLA matrix makes the composite both biobased and biodegradable, reducing environmental impact."

They then used what they learned with Bundle to create this much more refined Branch chair:

"Building on our knowledge of flax fiber/PLA composites, we wanted to explore how the composite could be combined with other materials. The result is a side chair with a beech wood veneer frame and a thermo-pressed composite seat, balancing strength, sustainability, and a refined organic form language. Designed for practicality, Branch is stackable and weighs 4.5 kg."

You can see how much work they put into the prototype and creating the molds for it:

You can keep abreast of Bundle's work here.