For daily cleaning of oil-finished furniture, a dry cloth is all that is required as the finish preserves the natural structure of the wood. Water should be avoided, as it displaces the oil in the wood pores, in addition to contact with chemical substances that may create stains or halos. A light protective oil may be applied from time to time to revitalise up the piece of furniture.  When cleaning flat surfaces, motion should be horizontal or vertical and be parallel to the grain of the wood as much as possible, avoiding circular motions which may create halos. It should also be remembered that real wood furniture exposed to direct light changes its colour over time. This change is considered to be a natural process of oxidation of the raw material.