If you've spent any amount of time looking at old clothes, in museums or in books, you've probably found yourself faced with a garment that you can't imagine being worn by any real person. It could be a pair of miniature kid gloves embroidered with elaborate pastoral love scenes, too exquisite to be misshapen by anything so brutishly human as a hand; a waistcoat so weighty with needlework it saps your joie de vivre just to imagine slipping it on; a corset with slender, smile-like bones spaced a quarter of an inch apart, its very meticulousness a reprimand to real-life flesh. Old clothes can be wonderful, but sometimes, their great beauty notwithstanding, they can be frustrating, too. The droopy lace trim on a cuff, the paint worn off a metal button, are the remnants of real lives. But without people inside them, old clothes often seem all too quiet, representing lives remembered only in whispers -- never anything so audacious as a shout, a burst of laughter or a fit of tears.

That's why the work of Sandy Powell, the costume designer who won an Academy Award for her work on "Shakespeare in Love," could be considered a kind of fanciful flourish on the study of serious fashion history. Powell's costumes are as accurate as movie clothes need to be. But she's gifted in subtler ways: She has a knack for giving her costumes emotional accuracy. In movies like 1997's "The Wings of the Dove," and last year's "Velvet Goldmine" and "Shakespeare in Love," she sends her costumes out to do a pretty complex job -- and succeeds on every count. The clothes tell a small story about the period in question. They move beautifully when necessary -- and constrict when necessary. And they always represent something of the character who's wearing them, without sending a crushingly obvious signal. Are the farthingales supporting the ladies' dresses in "Shakespeare in Love" precisely the right shape and size for the year 1593? Who knows? But seeing Judi Dench as Queen Elizabeth rustling along in her heavy, pearl-festooned skirts gave me such an unshakable sense of the character -- she's like an angry gilt cloud, annoyed no end at being earthbound -- that I couldn't have cared less. Powell understands actors, movement and the significance of clothing in a historical sense, but her costumes go even further. In helping an actor bring life to a character, they give you a sense of what old clothes were like when they had life in them.

The outfits Powell conceives can be sumptuous looking. But no matter how beautiful or extravagant they are, they always look like clothes for real people. In that respect they deviate significantly from the tradition of the luxurious costume epic -- for example, '50s extravaganzas like "Desiree" or "Scaramouche," in which the dresses are terrific fun to look at but tend to resemble birthday cakes from an Italian bakery. Yet as intrigued as Powell is by the language of clothing, she never forgoes aesthetics. For "The Wings of the Dove," an adaptation of the Henry James novel, Powell convinced director Iain Softley to set the story in 1910 instead of 1902, arguing that the clothing of that period was more bohemian, more freeing. Then she went to town, putting the lead actresses, Helena Bonham Carter and Allison Elliot, in cocoon cloaks appliqued with floral designs poised precisely between Art Nouveau and Art Deco; broad-brimmed, rakishly tilted hats; and sheer, shimmery Fortuny-pleated gowns that transform the women into living caryatids. The beauty of the characters' clothes lies partly in their very casualness. The women's velvets, for example, always look just slightly rumpled; the chiffon veils they wear for touring Venice look as if they were tied on with only half a care. These don't look anything like clothes that had been entrusted to the wardrobe mistress's care until just before the cameras started rolling. They look as if a character had been wearing them that morning as she set out to do an errand, returned later to write a letter or two, dropped by a friend's house for tea. They're clothes that, their period look aside, are just like the ones we wear today -- in other words, they have a personal history built right in.

That's a conscious choice on Powell's part. "There's a beauty in dirt," she told the New York Times Magazine last year. "When I go to the movies, I think, Why is that dress so clean? The boat is going down and they look perfect. You want to have beauty in a film, but if something looks a bit worn, a bit soiled, it usually has more depth."

That's especially apparent in Powell's costumes for "Shakespeare in Love." As elaborate as the garments are -- many of them are trimmed with beads, embroidery and even metal filigree -- none of them have that garishly new, shiny look that signals "rich." Like old money, they speak a lot more quietly. The brocades and metallic laces look just a little corroded, which gives them both a degree of immediacy (these are tactile clothes -- they look like they'd be wonderful to touch) and a sense of history (they've been around the block a few times -- in the late 16th century, not even rich people had all that many garments).

There's always a sense of energy to Powell's work -- it never looks staid or stagy. And for a designer so young (she's in her late 30s), Powell already has a formidable risumi. She started out designing for the London stage in the early '80s, and did her first costumes for film in 1985, with Derek Jarman's "Caravaggio." Since then, she's worked numerous times with Neil Jordan ("The Crying Game," "Michael Collins," "Interview with a Vampire," "The Butcher Boy"), and she received her first Oscar nomination in 1992 for Sally Potter's film of Virginia Woolf's "Orlando." Powell is frighteningly prolific. She received Oscar nominations for two 1998 movies ("Velvet Goldmine" as well as "Shakespeare in Love"), but she also designed costumes for last year's "Hilary and Jackie" (the story of cellist Jacqueline du Pri). Her next project is an adaptation of Graham Greene's "The End of the Affair" set for release later this year, starring Julianne Moore and Ralph Fiennes.

Powell has worked on such a wide range of movies that it's impossible to pinpoint her as a designer with an affinity for any particular era. In "Orlando," she devised costumes for a gender-switching hero/heroine who travels through several centuries: We see Tilda Swinton in Elizabethan doublet and tights, a massive ice-blue satin gown laden with rose garlands circa 1750, and a Jane Eyre-style black day dress. It's particularly interesting to compare the Elizabethan costumes in "Orlando" with those in "Shakespeare in Love," which obviously had a much bigger budget. The clothes may be less elaborate in "Orlando," but they're just as inventive: Powell gives Quentin Crisp's Queen Elizabeth (!) a ruff made of quivering metallic quills, a forerunner of the savagely magnificent peacock-feather ruff she would later do for Dench's Elizabeth. And if you look closely at "Orlando," you can see how Powell managed to fudge elaborate details on the cheap -- using a pleated length of grosgrain ribbon as a decorative cuff on an Elizabethan jacket sleeve, for instance.

The clothes in "Hillary and Jackie" evoke a mood and a time that's much closer to our own, showing us little English girls in early-1950s hand-knit Fair Isle sweaters and caps; later, we get a swinging-'60s Jacqueline du Pri in a red vinyl minidress and shiny black car coat. And Powell must have had a field day with "Velvet Goldmine," set in London in the early '70s. Although the movie's outlandish glam-rock confections, replete with spangles and feather boas, are what stick in people's memories, the "street wear" garments Powell devised for the characters are actually more effective, and brilliant in the way they evoke both the mood of the era and the sensibilities of the characters who wear them. The opening sequence shows a gaggle of kids running down the street in bell-bottoms, tiny T-shirts and Edwardian thrift-store fare, set to Brian Eno's "Needle in the Camel's Eye." It's a euphoric opening, and the clothes play a big role in it -- they're clothes for playing dress-up, part of the tool kit teenagers use to reinvent themselves, along with music and sex and drugs and whatever else. One of the movie's central characters -- an ambitious and sexually adventurous party girl, played by Toni Collette, who's ultimately crushed and humiliated by her rock-star boyfriend -- is a vision of careless, blissful freedom in her '70s jewel-colored velvets and quivering feathers. When we see her character circa 1984, after having fallen on hard times, her anonymous black shirt and pants and aggressively somber silver jewelry mark her as a person who's chosen to recede and wither, in a wrenching contrast to her younger, bolder self.

"Velvet Goldmine" and "Shakespeare in Love" may seem like two disparate projects for one designer to have worked on in the same year, but they're really just an unusual and slightly mismatched set of bookends. Because they're both about performers, people who devote themselves to creating new, miniature worlds for audiences, they're both excuses for lots of excess and pageantry and rich fabrics -- a costumer's dream. But even though "Shakespeare in Love" may seem like the less contemporary of the two pictures, in some ways it's actually more modern, with its little anachronistic jokes and often breezy dialogue. Its story is a piece of whimsy held in place by a few real-life historical figures and a fragile fact or two. And because it's set in a time none of us actually remember, it's relatively untainted by nostalgia.

In fact, what's striking about the costumes in "Shakespeare in Love" is how modern they are -- they're more like stylized love letters to the clothing of the era than faithful re-creations. Powell admits certain sacrifices of historical accuracy: Reportedly, Miramax studio executives wanted to make sure the men wouldn't look "silly" in their tights, so Powell made the jackets a little longer. But even Powell's sacrifices have the ring of truth. It was a stroke of genius to put Joseph Fiennes' young Will Shakespeare in a quilted, fitted gray-blue leather jacket -- to reincarnate him as a sort of Elizabethan Wild One. If you're watching carefully, you'll notice that sometimes the jacket is worn as a vest, sleeveless, over a loose-fitting shirt. I'm not sure zip-off sleeves existed as an option in the late 1500s, but it's an idea whose time should have come long ago. Will's jacket is a marvel of dawn-to-dusk versatility, the kind of thing that could take you from an early morning of scribbling with a quill pen through a sword fight to a late night of revelry and carousing -- without even a change of accessories.

Yet it's the dresses and jackets Powell devised for Gwyneth Paltrow as Viola that stand out most. Viola's costume changes are almost a plot device -- they help move the story along, if only because you wonder what she's going to turn up in next. The detail on each of Viola's costumes is a source of wonder: The filigreed metal "cages" that encase the cap sleeves of one of her dresses are almost like jewelry in themselves. The blue velvet jacket she wears when she's disguised as a boy looks fairly undistinguished until you see it from behind, particularly in the scene in which she reveals her identity to Will. Then you notice the rows of tiny tucks lined up along the collar, fanning out like the sun's rays. They seem like a frivolous detail -- who, save clothing junkies, is going to be looking that closely? -- but in addition to being simply beautiful, they're probably a shaping device, allowing the collar to fold softly around Paltrow's swan neck.

The lines of Viola's clothes tell us almost as much about her as her spoken lines do. Powell puts her in iridescent pleated gauzes, a golden peach ball gown that shimmers like a dragonfly's wing, a pale aqua dressing gown that looks suitable for an undersea princess. Even her high ruffled collars don't restrict her movement; there's always something light and airy about the way they frame her face. Viola seems sparrowlike, free, a delicate but willful creature that could be borne on the air. Only in her heavy, pale-gold wedding dress -- worn as she's being married to a man she doesn't love, an arrangement she's bound by law and family duty to honor -- does she look stiff and restricted. Not even her flowing wedding veil lightens it.

The wedding gown is the only one of Viola's dresses in "Shakespeare in Love" that's "wrong" -- which is precisely what makes it right. Viola moves differently in it; she's more tentative, uncertain, and suddenly, less girlish -- its thick quilted bodice seems to be her first lesson in feeling weighed down and bound. Of course, in real life, Elizabethan women's clothes were mostly uncomfortable and restrictive by today's standards. That everything Viola wears, save for that wedding dress, looks so light, so casual in a way, is part of Powell's triumph. She's not out to capture history in the circumference of a farthingale or the diameter of a ruff. She's out to write another kind of truth -- a kind of truth that anyone in a Polartec pullover and a pair of jeans can relate to -- in the drape of a skirt or the cut of a sleeve.

And to suggest that if the greatest playwright who ever lived had had the chance to reinvent his jacket as a vest by zipping off the sleeves -- well, he just might have taken it.