Skirting Tradition : Body-conscious brides can wed something old and something new in gowns that change silhouettes from the ceremony formal to the short-and-sweet party dress or shapely sheath.

Brides once had to make a lasting commitment to either a traditional wedding gown that covered them from head to toe or a more revealing dress that was fun to dance in but shocked the minister.

Now brides can have their wedding cake and eat it too. They’re finding wearable bridal gowns that can change silhouettes during the course of the big day.

They can play the part of the blushing bride in a long skirt and train at the ceremony, but at the reception, they can ditch the train or whip off the over-skirt and be transformed into a party girl in a slitted sheath or a mini.

Some of these convertible gowns feature long sheaths with trains that detach for making the rounds at the reception. Other dresses are even more innovative: A long, full skirt can be peeled away to reveal a short lace mini-dress or a plain sheath.

Gowns that change shape--and a bride’s attitude--are a growing part of the bridal market, according to Barbara Tober, editor-in-chief of Bride’s magazine.

“It’s what designers are doing. There are all sorts of variations--lace sheaths with tulle skirts, cocktail-length dresses with detachable trains. One dress comes with a coat and matching pants,” she says. “Second(-time) brides want gowns that have another life.”

Body-conscious brides prefer mini-dresses or long sheaths that come with detachable trains and over-skirts, according to Laurel Mungo, buyer for Mon Amie in Costa Mesa.

“These girls work hard at having nice bodies, and they want to show them off,” she says. The minis “are a little more updated and sophisticated. They’re for the bride who’s going to do serious partying at the reception. She can move around.

“Usually a bride takes off the skirt just before or after the first dance.”

Mon Amie’s convertible gowns come in everything from a strapless to a high-neck silhouette.

“They range from gowns with a detachable train in back so you can see the mini as you walk down the aisle to short dresses with long skirts that wrap all the way around so you can’t tell it’s a short dress underneath,” Mungo says.

One sleeveless sheath by Amsale comes in silk-faced satin with a sheer neck of chiffon and a satin train that attaches to the dress in back under a row of satin roses ($1,815).

Another indulgence is the sleeveless satin mini covered with lace and rhinestones with satin bows on the shoulders and a full wrap tulle skirt with a bow in front from the Diamond Collection ($2,465). Budget-conscious brides can choose an off-the-shoulder satin mini with lace detailing and a detachable full tulle skirt from Forever Yours ($498).

Without the bulky train, some gowns can even be worn again to other occasions--an idea that sounds novel but is actually an old tradition. Before the 20th Century, brides wore their gowns during their first year of marriage to parties and operas. After World War II, when inexpensive synthetic fabrics became available, brides could afford to buy a one-time gown that was expected to be handed down to their daughters.

Still, if a gown looks anything like a wedding dress, the bride has limited choices of where she can wear it, says Carolynn Young, co-owner of The Bride in Newport Beach.

“It would have to be worn as a ball gown. You wouldn’t wear it to a dinner party,” Young says.

Her brides favor more formal long sheaths that look like traditional gowns when worn with their detachable trains. Among the designers pioneering the look, Norma LeNain of Los Angeles makes intricately beaded sheaths ($3,500 to $7,000), Young says.

“The detachable trains are convenient,” she says. “When you get into the heavily beaded dresses, it’s a lot of weight to carry around.” Her favorite gowns, however, come with trains attached.

“This is one day in your life when you can wear a train. You don’t want to look like you’re just going to a ball,” she said. “There’s nothing more beautiful than a girl dressed in a long gown with a long train.”