They are easy to clean with warm water and a microfibre cleaning cloth. Never use solvents, bleaching agents, abrasives, chemical detergents nor waxes. If the Kosmos is used outdoors, always cover it completely with the optional cover when you are not using it, as the cushions are not 100% waterproof for reasons of ventilation. The cushions should be cleaned periodically in order to maintain its appearance and to prevent build up of dirt and bacteria. Lacquers and inks, strong cleaners, detergents and solvents such as thinner, acetone or alcohol can be very effective in removing stains, but cause immediate damage and contribute to the deterioration of the material. The use of such cleaners is at the owners risk.