How solvent loosens oily soil
“Dry” describes the cleaning liquid, not the condition of the clothes: garments are immersed in a solvent rather than water. Many dry-cleaning solvents dissolve greasy substances that water alone does not readily lift. The solvent can move through a load of fabric, loosen that soil, and carry it away without making some delicate fibers swell as much as they can in water.
Perchloroethylene, often called perc, has long been a common solvent, though cleaners may use other solvents. Dry cleaning is not automatically safe for every stain or garment; the right method depends on the fabric, dyes, trim, and type of soil.
The cleaning cycle also recovers the solvent
In a modern machine, clothes rotate in a drum with solvent, much as laundry tumbles in a washer. The liquid is then drained and filtered to remove particles and soils. During extraction, the drum spins out much of the remaining solvent. Warm air helps remove what is left, and the machine captures and reuses solvent rather than simply sending the whole supply away with the load.
That closed-loop process is a key difference from ordinary washing: the cleaning liquid is collected, cleaned, and put back to work. Water-soluble marks may need separate treatment because a solvent that is good at dissolving oils is not necessarily good at dissolving every kind of stain.
Why the shape survives
Water can cause certain fibers to swell, relax, or distort; agitation and drying can add further stress. Solvent cleaning reduces those effects for garments that are vulnerable to them. Afterward, a cleaner may press or steam the clothes to restore creases and shape. The result is not simply a garment that never got wet—it is one cleaned in a liquid chosen to remove particular soils while limiting the changes that water and handling can cause.
