Rather than ever-higher cotton thread counts, these covers get that silky-soft feel by using a polyester and spandex mix more often found in athletic wear. The product, available online since 2009 and at Bed Bath & Beyond since April, retails for about $200 a set.
It could represent the next generation of bedding in the more than $3 billion sheet-and-pillowcase industry, according to experts.
"The next market for performance fabrics is the home textiles area," said fiber expert Mark Sunderland, assistant dean in the College of Design, Engineering and Commerce at Philadelphia University. "The public is ready for that."
The performance fabric bedsheet, he allowed, is a novel way to push the trend. If it takes off, the cotton sheet might well go the way of the cotton T. "The days of putting on a cotton T-shirt and running for five miles have long gone," he said. "A Little Leaguer needs to put on a $40 performance shirt."
Sheex promises a better night's sleep with its "sleep-fit technology," a claim that sleep experts have not fully embraced. The sheets tout their moisture-wicking and breathability properties - aspects associated with workout shirts. But do those characteristics improve the quality of sleep?
Sheex has partnered with the National Sleep Foundation to promote good sleep practices, and this collaboration suggests one answer to this question. "Sleep is as important as diet and exercise," said Tom Clifford, director of development at the sleep foundation based in Arlington, Va. "It is really one of the three legs that hold up the stool. So much about American culture is go, go and go, and people end up cheating sleep."
The group's independent tests, he said, show that Sheex sheets "perform as described. . . . There's a wealth of anecdotal evidence out there that these sheets are providing a practical solution."
For sleep experts, however, the jury is still out.
Many factors affect quality of sleep, including stress, medications, and whether your partner in bed snores, according to Richard Friedenheim, medical director of the Sleep Disorders Center at Abington Memorial Hospital. Sure, temperatures also can affect sleep quality, he said. But studies have not conclusively shown that influencing ambient temperature results in less sleepiness or better productivity the next day.
"Given the lack of clinical trials or clinical correlation, I would proceed cautiously, especially given the cost," Friedenheim said. "It is not clear that a bedside fan could not accomplish the same goal."
The product is cool - literally. When I tried out a set, I loved that I didn't have to constantly flip my pillow over to escape the cotton inferno. It maintained a comfortable temperature. I also luxuriated in the softness of the fabric against my cheek - noticeably better than my usual linens.
But the steep price was a turnoff, and made me all the more annoyed when my dry feet kept snagging on the bedclothes. (Marciniak urged a pedicure.) My husband didn't care for the stretchiness, which can almost feel like a tug-of-war when pulling the covers back at night. However, the stretch does make putting on the fitted sheet a snap.
At Bed, Bath & Beyond, some online customer reviews noted similar complaints. Overall, though, the product got a star rating of 4.4 out of 5. Menopausal women appear to be the biggest fans.
Patty Carlis, 62, is one. The retired educator who lives in Allentown but grew up in Mount Airy decided to try a glacier blue set after meeting Marciniak in the locker room of an Allentown fitness center and hearing about the new product.
"My problem is night sweats," she said. "I have not taken the sheets off my bed except to wash them. I think they're so comfortable." Her grandchildren sometimes share the bed and have fun playing with the stretchy fabric, she said.
Sheex originated in just such a locker room conversation. Sometime after she became a basketball coach in 2003, Marciniak bought Walvius a pair of performance material athletic shorts just like her own favorite pair. Walvius loved the feel of the fabric and the way it fit.
As the story goes, Walvius made an offhand comment: "I would love to sleep in this stuff."
Marciniak looked at her and replied, "Let's do it."
After USC business students did a market feasibility study and presented "numbers that were almost unreal," the women decided to leave their day jobs in 2008 and jump into the bedsheet business.
Soon enough they figured out why no one else had made sheets like this before. The fabric can only be knit in certain widths, which are not wide enough to cover a queen- or king-size bed. Sheex solved the problem with a seam - flat-locked as in athletic wear - that extends its reach.
"The learning curve was big," Marciniak said.
"Bedsheets are not sexy, edgy, cool," she said, alluding to Sheex's motto. "They should be. You spend a third of your life in bed. It's a big deal."
Contact Lini S. Kadaba at Lkadaba@gmail.com.