WoW! Natural and reusable coffee mug. The outside of the mug is made of 100% FSC-certified cork, which is both biodegradable and renewable. The inside of the mug is made of a compostable material called polylactide (PLA). The two are fused together using a patented technique (which does not involve the use of glue) to create a double wall that is not only durable, but also keeps your drink warm for hours. The perfect combination of design, functionality and durability. Capacity 350 ml. About PLA Polylactide, or Polylactic Acid (PLA) is a thermoplastic aliphatic polyester derived from renewable resources. What does this mean? It means that PLA is a biodegradable material made from corn starch produced by plants - natural and renewable. Lactic acid is produced by the fermentation of that corn starch, creating the fibres used to make PLA. This environmentally friendly process converts natural resources into the ideal sustainable material. Each item is supplied in an individual brown cardboard box.