coming clean; The care tag reads dry-clean only.

Byline: Jane Herman

You are familiar with this scenario. A favorite blouse or dress or skirt has come back from the dry cleaner looking totally thrashed and lackluster. Lifting the plastic wrapper, you gasp: It smells of chemicals; it's lost its shape and its shine. What happened? What mad torture did your treasured garment endure to end up in such sad condition? You want-no, need-to know. The future of your most delicate, expensive, and sentimental pieces depends on it.

Uncovering the mystery of dry cleaning begins with one basic truth: It is not really dry. It is very, very wet. The process is dubbed "dry" because compound cleaning solvents are used in lieu of water, which can shrink and stiffen fabrics like cashmere and silk. In most cases, when clothes are dry-cleaned they're submerged in a liquid solvent and exposed to heat inside a huge industrial machine that can hold up to 100 pounds of clothes. (The machine washes, rinses, and then tumbles its contents until they are no longer sodden.) Finally, steamed or pressed, each garment is draped on a wire hanger and packaged with tissue paper and a clear plastic casing.

Simple enough. That is, if all you have to clean are simple clothes made of simple, trouble-free fabrics. The problem-or perhaps the challenge-is that fall's collections showcase an extraordinary mix of materials, from thick, extra-nubby knits to exotic luxury leathers, with delicate, even flammable, trimmings of things like ostrich feathers and mink. At Dolce & Gabbana, a wool coat dotted with giant gumball-size pearls also features elaborate military-inspired embellishments, embroidered in metallic thread. Oscar de la Renta made a ballerina skirt of black tulle and sharp, shiny plastic flowers. Marc Jacobs's knotted, sequin-covered cashmere coat trimmed with a fox-fur hem for Louis Vuitton takes the cake: What to do when the coat needs a good, hot wash, and the iridescent plastic discs that cover it are sure to melt?

"Unless there's a distinct reason why, I would dissuade someone from ever cleaning it," says Bernard Dicks of Meurice Garment Care, an upscale cleaner in Manhattan. Dicks takes a good look at the coat, pointing out its many challenges: The gold zipper would have to be removed; the fur would need to be treated separately; the sequins would curl with even the gentlest steam. He notices that the wire hanger on which the coat is hung is dirtying the lining inside the shoulder. "Let's start with getting it a better hanger," he says.

The basic hitch is that no one solvent properly attends to all of the many materials that make up these pieces. In the United States, about 75 percent of dry cleaners use perchloroethylene, or perc, a clear, nonflammable chemical liquid that does wonders for cashmeres, ...