Regular periodical cleaning will guarantee that your sofa will serve you for as long as possible.
For dry dirt use a brush with soft bristles or vacuum cleaner at the medium setting. If the sofa is stained, a white and non-abrasive cloth will come to the rescue. Rub a wet cloth delicately, working from the outside of the stain towards the center and dry it immediately afterward.
For stains caused by greasy substances, using an absorbent paper, soaked in a diluted soap solution will do fine.