Coffee shells and e-waste become a marble-weight material called Matek

Project Materia, an independent Copenhagen-based exhibition platform, brought together nine international designers around a single material for its 2026 edition: Matek, a circular material made by Danish brand Mater from coffee-shell waste, sawdust and recycled plastic.

The show opened in June at a space on Købmagergade during Copenhagen's 3 Days of Design festival. Founded by design studio Tableau and art brand Edition Solenne, the project worked with bronze, marble and glass last year; this year it turned to a material with no inherited history.

Mater's head of marketing and sustainability, Trine Mark Egeberg, said the material is largely made from electronic waste plastic sourced from phones and laptops, mixed with coffee-shell fibre and sawdust from wood production. Matek is supplied to designers as flat sheets.

Working without a brief, the nine participants explored different approaches: Sophie Dries glued coloured sheets together and turned them on a lathe into candleholders, Willem van Hooff built an archive cabinet, and Lea Colombo produced a stool referencing sacred geometry.

The collection is now travelling: it will show at Paris Design Week from September 10-12 and at the London Design Festival from September 14-17. Tableau founder Julius Værnes Iversen said last year's project used some of the oldest materials in the world, while this year's uses some of the newest.