Eco Friendly Cork Cork and tree rubber are 100% biodegradable. Cork is made from the bark of a tree commonly found in the Mediterranean area around Spain, Portugal, France, Italy, Morocco, and Tunisia. The cork is harvested by stripping down the bark of trees, which naturally regrows making it a highly sustainable resource. The trees absorb more carbon dioxide after the bark has been removed, which means using the bark leaves a positive environmental impact. There’s no cutting down or wasteful residue in the process, making it an ideal renewable resource.