Frankfurt-based furniture brand e15 celebrates 15 years of the BACKENZAHN™ side table with the launch of a black oak edition. BACKENZAHN™ is designed by e15’s founder, Philipp Mainzer. The side table is made from wood from the centre of the tree, which forms characteristic cracks as it dries. A vinegar solution is applied to the untreated oak to loosen the iron particles, followed by a mixture of natural ingredients to transform it to a matte black finish, which is then sealed with wax. e15