In the basement of a house in a cookie-cutter subdivision in suburban Ontario, down a winding staircase and past the children running around a playroom, a pregnant woman sits very still as her protruding belly is lined with gooey strips of white plaster.

"I was nervous that it might feel uncomfortable," says Michelle Plant, who at 34 weeks pregnant, is forcing herself to kneel, leaning back on a supporting chair, wearing nothing but a pair of black underwear. She will remain in this position for about half an hour, until her breasts and belly are covered with two layers of the warm white strips that will eventually form a cast of her tumescent body.

"What does it feel like? It feels a little like I'm in Pilates class at the gym, even though I haven't been to the gym in months. I know it sounds funny, but it's that same tightness -- not uncomfortable, just a sense of heaviness about your body," says Plant, a 34-year-old from Ancaster, Ont., who is due at the end of this month.

By the time the artist pulls away the hardened cast from her body, Plant's underwear will be soaked and her legs and back will be a bit stiff from the sustained squatting.

It is a small price to pay for the posterity of pregnancy, says Plant, who is like a growing number of women keen to have these tangible, lasting reminders of their pregnant form.

These kinds of pregnancy casts have also been done for couples, where the man's hands are wrapped around the belly; mothers and daughters, where the unborn female babe has been part of a pre-birth, three-generations image, and even for an unusual take on the traditional baby shower.

The belly casts, belly masks or pregnancy body casts range from the basic do-it-yourself kits available in craft stores and by mail order, all the way up to a full-service, spa-like experience that includes a customized artistic finish of the cast. Companies with names like Red Hot Mama Inc. and The Birth Place sell kits that include plaster cast material, petroleum jelly, a drop cloth and gloves for about $50-70 including shipping. It is the most popular item offered online at Your Birth Connection, averaging about 15 or 20 sales a day. Full-service belly casts, such as the one that Plant is undergoing, can run as high as $300, depending on the artistic finish.

Most of these casts preserve a full-frontal view of the swelling form all the way down from the top of the chest to the top of the thighs.

They have become the modern mother's version of bronzed baby booties. The popularity of the belly cast symbolizes a significant shift in attitude about pregnancy, replacing a tradition that commemorates the wonder of the tiny newborn with one that focuses on the mother and her life-giving body.

"A belly cast is an amazing way to memorialize your pregnant shape," says one online belly casting company.

"This is a wonderful way to honour and preserve the amazing reality of how your body changed to grow a baby," trumpets another. "A photo captures your body's changes two dimensionally, but a belly cast adds the dramatic third dimension of depth. In the years to come, you can view it from all angles, touch the curves, and explore the inner concavity where your baby curled up waiting to be born."

Susan Balaz, the Burlington, Ont., artist doing Plant's belly cast, says this new pregnancy keepsake is all about "women celebrating their bodies and the fact that they've got a life growing in there."

She uses a medical bandage that is plaster-infused, similar to those used to make old arm and leg casts. She started out using a craft product but found it was too messy, and frowns on using old-fashioned plaster casting directly on the skin because it can cause a burning sensation.

As she works, she slides the plaster strips through warm water and, keeping them taut, applies each one to Plant's body. She works quickly and deftly, since it doesn't take long for the plaster to set (the cast can begin to separate from the body about 15 or 20 minutes after starting, which is why speed is critical). When it's ready, Balaz coaxes the belly cast away from the body by pulling on it lightly as Plant gently shrugs it off.

Balaz will put an extra plaster layer on top of the finished cast, to give it a hard finish, and then paint the cast according to the client's request.

She has painted everything from fairyland scenes to leopard-skin prints on her finished casts. She has decoupaged baby's ultrasound picture onto the belly cast, and has just finished one cast that the client wanted done in a tie-dye effect.

Plant wants hers to be painted a warm bronzy gold: "I have a 24-foot living room and I was thinking of hanging it on one of the empty walls, a bit nearer the back, so you have to be my friend to see it. I don't exactly want everyone who comes to the door to catch a glimpse of my body.

"I know this is not for everybody," she says. "My sister-in-law is pregnant and she is just disgusted by it."

The belly casting is one of her Christmas presents from her husband -- "He thinks I'm crazy, but he knows I wanted to do something like this."

She first heard about the concept on The Baby Channel on TV, and found out about Balaz, whose business is called Love's Memory, at a martini bar last summer.

"Sue's husband came up to me and said, 'Excuse me, are you pregnant?' I was about 16 weeks, but I wasn't really showing. I was wearing this funky halter top and I was thrilled that someone noticed my belly," Plant recalls. "He said, 'You should see my wife, she's in the business,' and he wrote it down on a napkin."

Balaz laughs at the story, but says she has built up a pretty steady business simply by word-of-mouth and approaching pregnant women like Plant and telling them what she does.

The former social worker, who has pixie-like good looks and an easygoing manner, decided to set up her own pregnancy body casting business after doing a cast as a gift for a friend. She began by travelling around to women's homes throughout Toronto, Niagara and even into New York state to do the casting, but ended up doing so well that she set up a small studio in her basement.

There is a tree painted as a backdrop on one wall; on another, in fancy lettering, is written, "Each Day Comes Bearing Its Gifts, Untie the Ribbons." While Balaz works, the music of Sarah McLachlan plays in the background; there are candles on the floor.

Melanie Dubruiel, of Hamilton, had a belly casting baby shower about a month before she was due with her first child, Jack.

"There were about 20 women all crowded in this one room at my mother's house while this was being done. I didn't think about it until the time, and then I thought it was going to be really embarrassing, but it was just fine," says Dubruiel, who is 20.

For the most part, the women at the shower -- her friends, her mother's friends, relatives, and even her aunts -- just kept talking among themselves, snacking and drinking while Dubruiel was lined with plaster.

She says she is normally quite a shy person, and so insisted on wearing a bra for the plaster (even though belly casting purists insist the unadorned breast is a better representation of the pregnant form) and having Balaz apply the first layer over her breasts in the privacy of a washroom before she came out for the full shower to see.

Plant has no such inhibitions -- this is her second pregnancy and she is clearly enjoying her bulging body.

Her son "told everyone at school today that I was going out to get plastered," she laughs. "I had to explain to his teacher that I was getting plastered the only way I could at this stage."

aowens@nationalpost.com