A fit model is a special kind of model who doesn't have to be beautiful. ("She can actually be really ugly. She totally can," said one designer.) Her job is to be a mannequin, but with human qualities, and all day she tries on clothes. You see, a garment must look a certain way to succeed, of course, but it also has to fit well and move with the body. Unlike a dress form, the fit model has limbs; they're intricately articulated, and she can move them with ease. She feels the clothes against her body, she thinks thoughts and then expresses them. Dummies have their own unique and valued features, too—they're a fantasy blend of measurements and symmetry. But none can replicate the many bizarre and marvelous human qualities that affect fit: a chest that bloats with breath, muscles that swell when flexed.

This model is a big deal to a company, because it customizes its full range of designs and sizes to her proportions. If her figure happens to be similar to yours, the system works—but if it fails, the shame is violating. Perhaps you've been jeans shopping, and out of everything in the store, not a single thing fits, from the slim tapers to the trouser cuts to the relaxed mid-rises. "Surely, there is something fundamentally wrong with the shape of my body," you thought to yourself—when, instead, you should've been blaming the fit model all the while. (Sometimes, misshapen fit models get hired, which is completely idiotic, but it happens. One major company's fit model had a sway back. Another's had fake breasts, and all the tops patterns had to be altered after she left.)

In choosing a fit model, the company wants someone just like its target customer: an ordinary person who is neither too tall nor too lean, for a change. But companies' decisions don't always make sense, or they end up cutting out entire demographics by choosing a rather skewed version of "average." Take Arika, an attractive Seattle- area fit model with blond hair and blue eyes. In one of her roles, she's a tops model for a large company targeting middle-aged women—but bewilderingly, she's decades younger, with a full bust and a slender torso, and a modest high-shoulder-point-to-apex measurement (this means her breasts sit pert). To the aging woman, Arika's body is nothing more than an impossible dream.

Arika has held many fit modeling jobs for many companies. She gets to interact with the newest clothes, and the money is insane: Fit models make $50 per hour at the low end. But she can't allow her weight to fluctuate by even three pounds—a bleak and looming demand. The fittings take several hours, and while she stands in a room before a group of designers, "They're thinking of me as a mannequin, so it's important I express my human needs. I often have to remind them I need a break—so I can take a drink of water or sit down and rest."

There's a good deal of manhandling. Something like the crotch seam is not only complicated, it's hard to see, so deeply wedged in its valley of butt and shadow. The technical designer has to touch where the seam rests on the model, and this gesture, usually so intimate, is performed with the same prompt yet weary manner of someone opening a can of dog food and placing it in a bowl. "I'm desensitized," says Arika. "I feel like my body is a commodity. It's harder to feel sexy."

It gets worse during outerwear development. Arika wears a shirt and sweater under a coat and stands beneath bright lights for hours while everyone studies her. Jackets with fur-trimmed hoods are especially brutal. Still prototypes, their shapes are off. "The hood is right in my face... I'm eating and breathing fur. I'm too hot, my eyes are bright red, I'm tired. I go home and use a neti pot to flush out my sinuses, and what comes out of me is like the lint from a dryer trap. This is the stuff I've been breathing in all day. Who knows what chemicals it's been sprayed with"—probably a disturbing potpourri of stain guards, wrinkle resistants, and fungicides for garments produced in muggy climates and transported on boats. They arrive unwashed from overseas factories and, sometimes, workers leave upsetting clues: "I've seen stuff on the samples that looks like blood," Arika says.

In one of these factories in a faraway town somewhere in rural China, a mannequin with Arika's body rests among the endless piles of clothes. Even though it's just a perfunctory fitting tool—used to test the garments bound to be shipped off and then tested again—the scene has a strange glamour. It recalls Jay McInerny's Bright Lights, Big City, a great book about loss and human pain and beauty just out of reach: The character encounters a window mannequin molded from his ex-wife, a model, taken while she "lay face down in a vat of latex batter for ninety minutes, breathing through a straw."

Special thanks to technical designer Victoria Walters.

Attention, makers of fashion and workers of garmentry: Let me know what you're working on at mjonjak@thestranger.com.