I like checking out bridesmaids' finery as much as the next guy, so I was thrilled the romantic comedy "27 Dresses" takes time for a dress-up montage starring our heroine, the selfless doormat Jane, played - and, remarkably, made tolerable - by Katherine Heigl.

The fashion show is for the benefit of a Manhattan weddings columnist (James Marsden, last seen getting creamed by cyclists to droll effect in "Enchanted"). Ostensibly covering Jane's sister's marriage, the reporter is in fact concocting a stealthy, pathos-ridden profile of the "perpetual bridesmaid" herself. Will Jane ever find a love of her own? Might it be with the very columnist taking notes on the contents of her closet and snapping pictures? Well, it's possible. And don't give me any of that "spoiler" nonsense. When it comes to telegraphing its narrative developments, this entire movie's a spoiler.

The eerily precise Heigl, who provided confident back-court support as the exile in Guyville also known as "Knocked Up," has no trouble filling a leading lady's shoes. She's just snarky enough to be interesting, and she knows how to take a fall. She's also a touch invulnerable; Heigl's automatic good-sport smile gets a dangerously extended workout in this vehicle. But the woman has timing. While you can refine and sharpen timing, you cannot fake it.

The material, by contrast, is pure polyester. With all the estrogen on this project - the director is Anne Fletcher, a former choreographer; the script is from Aline Brosh McKenna, primary writer on the tasty "Devil Wears Prada" adaptation - you'd think Jane might be defined by something livelier than a deadening crush on her employer (Edward Burns). Or an obsession with nuptials. Or a propensity for low-level, medium-predictable humiliation, usually instigated by her miserable brat of a sister, who ends up fiddling with Jane's boss while Jane burns. The sister is played by Malin Akerman, who lays so hard into her character's bitchiness, so humorlessly, you may feel like writing the studio and requesting that Heigl play both sisters in a demanding dual role.

Moviegoers are pretty easy marks when it comes to wedding-centric rom-coms. The ritual at their core is endlessly open to jokes as well as a reliable source of tears. "Four Weddings and a Funeral" is probably the best of our generation's bunch, despite the way Andie Macdowell said the line "Is it still raining? I hadn't noticed." "27 Dresses" pays homage to a film closer to its own weight class, "My Best Friend's Wedding," in a scene where Jane and reporter Kevin get sloshed and lead a sing-along to "Bennie and the Jets." (In the decade-old Julia Roberts comedy, the tune was "I Say a Little Prayer.")

My favorite performer in the movie, Judy Greer, is a deadpan killah as Jane's co-worker. She and Heigl deserve fresher stuff. Line to line, McKenna's dialogue can be tart and enjoyable, but the narrative itself is a wheezy pre-feminist fairy tale, piling up the occasions for Jane to eat it and eat it until the target audience is practically drooling for her prince to make things right. "I don't need to be taken care of, thank you," Heigl declares early on, tossing off the line with as much indirection as possible. The point of the line, of course, is to remind us what a dame needs most.