dry cleaning, system of cleaning textiles with chemical solvents instead of water. Dry cleaning is especially useful for materials such as wool, silk, rayon, and delicate synthetics, which can be damaged by water or traditional washing.

The process of dry cleaning begins with the inspection of garments for stains, damage, and fabric type. Stains are treated individually with spot-cleaning chemicals designed for specific types of stains, such as ink, oil, or protein. Clothes are then placed in a dry cleaning machine, which looks similar to a large front-loading washing machine. Instead of water, however, a chemical solvent is used. The machine gently rotates the clothes, soaking them in solvent to dissolve stains. The solvent is drained, and the clothes are gently dried using warm air to evaporate any remaining solvent. Remaining stains are treated again, and garments are pressed, steamed, reshaped, and prepared for return to the customer.

Since the mid-20th century, one of the most commonly used chemicals in dry cleaning has been perchloroethylene (PERC; tetrachloroethylene), which is very effective at removing stains. PERC, however, is potentially toxic to humans, and its use is being phased out in some regions, including in the United States. Alternatives to PERC include petroleum-based hydrocarbons, silicone-based solvents, and liquid carbon dioxide; although safer and more environmentally friendly, these chemicals also tend to be less effective than PERC.