Our light NORTH was initially made from brushed copper. This version is not available any more. Please only follow these care instructions if you own one of the lights in brushed copper. To clean it, please first make sure that all areas requiring treatment are clean and dry and that the light is disconnected from the power supply. Distribute the citric acid undiluted onto the metal surface by spraying it or applying it with a sponge. For polished surfaces, we recommend using the soft side of a common household sponge, brushed surfaces can be treated with the coarse side of the sponge, moving it in the grinding direction. After a few minutes, you need to rinse the metal surface with clear, lukewarm water. Make sure that the acid is completely removed as it may cause discoloration. After rinsing the surface, wipe it with a soft, lint-free cloth without applying any pressure.