One morning last week, I went looking for a bra. What I needed was one of the rarest of undergarments: the unlined white cotton bra. I soon discovered that simple, functional lingerie is just not acceptable anymore. Even on our most average days – when we have 10 hours of work to do, when we are grumpy, and when no one will see us with our clothes off – we should still be wearing fancy, sexy lingerie. How very French.

At the Victoria’s Secret flagship store on 34th Street, I could buy a Very Sexy push-up bra, a satin Ipex bra, a “balconet” bra, and a $198 magenta bra designed by Roberto Cavalli. I could buy a pink teddy adorned with feathers and designed by Betsey Johnson, a roomful of lotion and cosmetics, and panties that read “cupcake” or “just play nice.” What I could not buy, even if I asked very nicely, is a regular, white, unlined cotton demi-cut bra.

The basics – you know, the underwear you wear under your clothes, not instead of them – are becoming the most elusive part of the bustling intimates market.

That’s not to say they don’t exist. At the 22,000-square-foot Herald Square store, a slim shelf of all-cotton underwear in white, red, and black is nestled at the back of the second floor. There’s one rack of very full-coverage, aggressively anti-sexy white bras to match.

Even in the company’s catalog, where there’s a larger selection of simple white cotton underthings, it’s the Very Sexy collection and the Angels collection that get all the attention.

The manager on duty said there’s little demand for cotton because “it’s a shaping thing” – one layer of it doesn’t provide enough coverage on its own. But she pointed out another rack of cotton-lined Body by Victoria bras, and reassured me that there will be more cotton on sale during the summer months.

Undeterred, I headed across the street to the Gap. After all, while Victoria’s Secret hawks sexiness, the Gap sells everyday style. Sure enough, the downstairs Gap Body area was much less sexed-up than its seductive neighbor – no intimidating mannequins or spangles. But no white cotton bras, either.

A Gap spokeswoman, Erica Archambault, said that nonetheless, the company’s focus is essentially on “the stuff that you wear every day.” But that’s not to say it eschews sexiness: What the Gap provides, she said, is “the bras that women love to wear every day and” – you guessed it – “that they can feel sexy in.”

Natch. But what if I feel I’m sexy enough already? What if – horrors – I don’t want to feel sexy?

The good news is that the Gap has expanded its intimates offerings because of the dearth of merchandise in the “everyday” category, according to Ms. Archambault. “Part of the reason why there’s a lack of that type of bra right now,” she said, “is because of the prescribed idea of sexy, from Victoria’s Secret and others, who have told women what is sexy. Whether it’s lacy and glittery or glossy and pushing up, it’s more like the life of a supermodel. … It’s trying to emulate Tyra Banks and it’s unrealistic.”

The American Apparel store on Houston Street, a veritable kingdom of cotton, sells white cotton bras that a saleswoman described as “more like a sports bra.” In other words, they flatten the chest and they don’t have an underwire – but they’re still progress.

A shopping trip before the holidays – the season in which men shop for women’s underwear – turned up far fewer basic lingerie items than a second trip this weekend. So it seems the bras women buy for themselves are more practical than those they’re given as gifts.

What about other intimate staples? Take the simple slip, which has a somewhat dowdy reputation. When Vassarette dressed up its basic designs, the company saw a spike in sales that had been flat.

“They’ve added lace in some cases and in some cases sort of a Pucci[-style] print,” a Vassarette publicist Erica Fineberg, said. “It’s become more a fashion item. It’s been doing very well. Especially the camis, where women like to wear it under sweaters. That’s been blowing out the store because they’re very sexy and fun and inexpensive.”

Have I been missing the boat? Maybe most women don’t want their basics to look basic?

For spring, Vassarette is pushing “sexy cotton” for its bras and underwear. According to promotional materials, “cotton just got cooler, hotter, sexier, funner. Bows and flows, satin and lace … are the details that define our new feminine, flirty, comfy, cozy SexyCotton bras and panties.”

That’s a lot of adjectives for a set of cotton underwear. But it’s a compromise I might be able to live with.