What Is Dry Cleaning? How It Works and When to Consider It

Most of us have dropped something off to be dry-cleaned, from everyday clothing like work uniforms or dress shirts to special occasion items like wedding dresses or tuxedos. One of the great benefits of outsourcing laundry to a dry cleaner is not having to think about how it gets cleaned. But as a result, the how of dry cleaning can be a bit of a mystery.

Maybe you've wondered what goes on once you've dropped your clothes off at the dry cleaner, and what, exactly, "dry cleaning" even means. This article will explain the dry cleaning process, the history of solvent-based fabric care, and when you might want to consider dry cleaning vs hand-washing or machine laundering.

What Is Dry Cleaning?

While traditional laundry uses a combination of soap, water, and mechanical action to clean clothing and household goods like sheets and towels, dry cleaning relies on solvents—rather than water—for cleaning. Merriam-Webster defines dry cleaning as "the cleansing of fabrics with substantially nonaqueous organic solvents." That is, cleaning fabrics without the use of water or water-based cleaning agents.

Dry cleaning is believed to have been invented in 1825. According to the National Library of Medicine, "The French Federation of Dyeing and Cleaning gave an account of a servant in the household of Jean-Baptiste Jolly in Paris in 1825 who spilled the contents of a lamp on a soiled tablecloth. When the tablecloth dried, the spots had disappeared. Use of volatile organic liquids to clean cloths became known as ‘French cleaning’ in Scotland and ‘chemical cleaning’ in Germany. Eventually, such processes were called ‘dry cleaning’ because they do not involve the use of water."

Highly flammable petroleum-based solvents, like kerosene and gasoline, quickly proved to be unsafe, leading to the invention of non-petroleum solvents for use in dry cleaning. One such solvent, perchloroethylene, has been widely used in dry cleaning since the 1930s. However, perc, as it is commonly called, is carcinogenic and toxic to the environment, leading to contamination of soil and groundwater when spilled; perc is highly regulated by the Environmental Protection Agency.

While perc is still widely used in dry cleaning, alternative solvents and cleaning methods have been developed to replace it with safer options. Typically referred to as green dry cleaning, these more modern solvents include synthetic petroleum, siloxane, and liquid carbon dioxide. Wet cleaning, i.e. the use of water-based cleaning methods and agents, is sometimes also used by dry cleaners as an alternative to perc.

How Dry Cleaning Works

"Garment care better describes what we do to clean clothes," says Wayne Edelman, a dry cleaning and fabric care expert and president of Meurice Garment Care, "because it is not just about dry cleaning. Some clothes need to be spot cleaned, hand cleaned, cleaned using water or hand washed." Those decisions are made after an item has been dropped off at the dry cleaner, which is when the following process begins.

Step 1: Garment Tagging

The first thing that happens when items are dropped off for dry cleaning is that they are tagged with a unique number. The garment tag ensures that dry cleaners can keep track of customers' belongings so that you get your items back—and not someone else's!

Step 2: Assessment and Pretreatment

After tagging, a visual inspection and assessment take place: Stains are marked, and buttons and embellishments are covered to protect them from damage. In some cases, buttons and embellishments may be removed prior to dry cleaning and reattached after the process is complete. If necessary, stains are pretreated.

Step 3: Garments Placed in Dry Cleaning Machine

Dry cleaning machines look very much like home washing machines, and they function similarly: Clothing and other dry-cleanable items are placed in the drum of the machine, and solvents are pumped in as the drum agitates the items to produce mechanical cleaning action.

Step 4: Inspection

At the completion of the dry cleaning cycle, garments are removed from the dry cleaning machine and inspected. If any stains remain, they may be pretreated and/or put through a second round in the dry cleaning machine. Embellishments and buttons are inspected for damage or, if they had been removed, reattached to the garment.

Step 5: Finishing Touches

If needed, garments are pressed, ironed, or steamed to remove wrinkles, often using a machine called a form finisher. Form finishers, which look something like a padded mannequin, provide a smooth finish by allowing dry cleaners to steam garments in the position in which it is worn.

Then, a final inspection is performed before the garments are covered in plastic and returned to their owner.

When to Consider Dry Cleaning vs Hand- or Machine-Laundering

Many items of clothing that are labeled "dry clean only" can actually be hand- or machine-laundered. To determine if a garment can be hand- or machine-washed, consult the fabric content information on its care label.

Cotton, linen, polyester, nylon, and spandex are almost always machine washable. Avoid the use of hot water and high-heat drying when laundering shrink-prone cotton and linen; nylon, which tends to be staticky, should be air dried. Spandex should not be washed with chlorine bleach. 

Wool, silk, rayon, and viscose do not react as well to wet cleaning, especially machine washing. Wool does not like to be overhandled, nor exposed to heat, which can cause it to shrink or become matted. Hand-laundering is fine for lightweight wool items, but heavy wool garments like overcoats should be professionally cleaned. Water damage and shrinking are common in silk, rayon, and viscose fabrics; dry cleaning is typically recommended for those fabrics.

In addition, there are certain factors to consider, including the item's fabrication, value, and meaning to you. "Items made with mixed materials, embellishments, suede, leather, and vinyl trim should all be trusted to a professional," Edelman says. "High-value items or precious heirloom items with particular stains should always be brought to a professional."