By Lisa Neff

Contributing writer

Some grow out of sleepovers.

Some don’t, but most likely call them something different in adulthood—tricks, treats, one-nights…

Some eventually get to bring their best friend home for good after enough sleepovers. And that’s when the ratty T-shirts, the cut-off sweatpants, the faded boxers and the retired gym shirts come out, replacing the carefully selected satin, silk or almost-not-there PJs intended to seduce.

But in the last 10 years there’s been an expanding market of fun and sophisticated sleepwear for those seeking to become the best-dressed but most-comfortably in their own bed.

Hipsters once used the term “cat’s pajamas” to refer to someone or something great, innovative and stylish. Pajamas, in the 1920s, were a relatively new fashion. The Cat’s Pajamas brand of poplin sleepwear borrows on the Jazz Age lingo and honors that notion of fashionable, stylish pajamas.

The creators of the Cat’s Pajamas are college friends Jenny Maxwell and Lynn Deregowski, who went looking for fun sleepwear about 10 years ago and didn’t find happening PJs to suit their tastes. So they created the California company to produce made-in-the-USA pajamas printed with images of coffee cups, snowmen, skis, and the ever-popular sheep. You’ve probably seen these nighttime threads on television—shows such as “Good Morning America,” “Will & Grace,” “Queer Eye for the Straight Guy” and “Buffy the Vampire Slayer.” New offerings include a hydrangea print in blues and greens, a paisley style and a design called Tuscany inspired with architectural elements. www.thecatspjs.com

Snuggle down: For the past eight years, BedHead Pajamas has been producing fine cotton flannel and cotton sateen PJs, the kind so comfortable it’s hard to shed them in the morning and head for work. A percentage of money from BedHead sales also supports the grassroots organization Esperanza, which seeks to stop the exploitation of workers in the garment industry and promote fair labor and housing programs. www.bedheadpajamas.com

Night fever: Our bodies are supposed to cool down at night, but many people suffer night sweats and hot flashes so intense that they have trouble getting a good night’s sleep. Wildbleu has designed a series of pajamas and sheets with a special wicking fabric to decrease the symptoms of night sweats. The sleepwear and sheets are four times more absorbent than cotton, but feel like cotton. And a heat release technology is woven into the fabric rather than applied afterward so it won’t wash out. According to the company, 50 percent of consumers order another pair within a week of trying the first. www.wildbleu

Butt yes: What’s old is new again. The PajamaGram Company has reintroduced its Red Drop Seat Pajamas. The supersoft, classic, union-suit-style pajamas are made of cotton rib knit with three-snap dropseats, full-snap fronts and feet made skid proof by treads—imagine them at International Mr. Leather. The pajamas can be made personal by adding a name to the “back end” dropseat. www.pajamagram.com

Creatures of the night and day: World Wildlife Fund’s 100-percent organic cotton pajama pants display the WWF panda logo and raise money for the protection of endangered species. The largest multinational conservation organization in the world, WWF works in 100 countries and is supported by 1.2 million members in the United States and close to 5 million globally. Revenue from its apparel line supports that work. www.worldwildlife.org

Cashmere comfort: Big Feet PJs makes a line of flannel, fleece, knight and, yes, cashmere, footed one-piece unisex pajamas. And this is the funny thing—they only come in adult sizes. www.bigfeetpjs.com

Hotel hospitality: Kimpton Hotels understands that sometimes folks want to feel vacation-pampered at home. The company’s retail website features dozens of products for homebodies to recreate hotel hospitality, including Kimpton Signature Pajamas with the luxury of a 300 thread-count experience. Exclusive to Kimpton, the pajamas feature a white-on-white jacquard sateen zebra pattern and are made with 100-percent Egyptian cotton, a portable form of Kimpton's exclusive zebra bed linens. www.KimptonStyle.com

Mattress music: Seeking a soundtrack for hitting the sack? At this month’s Consumer Electronics Show in Las Vegas, industry-insiders got a sneak peak at Sonic Impact’s first speaker system to sleep on. The BM101 panel audio system consists of panels that slide between bed mattresses and box springs—or underneath sofa cushions—to provide good vibes. Consumers can look for the speaker system this spring. www.si-5.com