Robin Rombach, Post-Gazette
	For Caitlin Smith, one incentive to lose weight was to get back into a pair of perfect-fitting jeans that she had kept from high school. "I just couldn't let them go," she says, and lost about 40 pounds so she wouldn't have to.

When Caitlin Smith of McCandless vowed to lose weight last spring, she followed an unusual strategy for motivation: She hung her favorite, once perfect-fitting jeans on the wall of her bedroom.

She was 40 pounds and three sizes away from getting back into them, but she had held onto them anyway.

"I just couldn't let them go."

The 20-year-old joined Weight Watchers and started working out every day. By mid-October, she had shed the 40 pounds and was again wearing her prized medium-washed American Eagle boot cuts.

The power of fashion -- and the perfect pair of blue jeans.

Jeans occupy a unique niche in global and especially Americana fashion because their comfort, durability and affordability have helped them transcend age, class and creed -- as well as defy fashion swings.

Yves Saint Laurent said many times that he wished he had invented blue jeans. Janet Jackson said she "can't live without jeans." And fashion journalist Diana Vreeland, the 20th century's most influential arbiter of style before her death in 1989, praised jeans as "the most beautiful things since the gondola."

You may not own a wristwatch, a button-down shirt, a trench coat or sneakers, but odds are you have some jeans -- and more than one pair. Like shoes, you won't buy them without trying them on first. When you find a pair that fits right in all the right places, you'll wear them until they're in tatters.

It's a big reason why the old styles never go out of style and why sales of jeans in the United States continue to grow. Sales for the 12-month period ending in September topped $15.7 billion -- an increase of 6.12 percent over the $14.8 billion generated the prior year, according to the NPD Group Inc., a leading provider of consumer and retail information.

The hottest trends for jeans this holiday season are indigo hues, higher waists and stovetop skinny. But if you'd prefer the more standard styles, they're on the racks, too.

In fact, although skinny jeans are considered "in," 70 percent of respondents in a recent People magazine poll said they will not buy that style this year -- regardless of which designers are making them and which celebrities are wearing them.

"Customers are not dumb," said Lawrence Scott, who recently designed and launched a line of jeans at his South Side specialty store, Pittsburgh Jeans Co. The average person doesn't buy something simply because a celebrity, designer or fashion magazine declares it a must-have, he said.

Especially in jeans -- where the importance of a comfortable fit often transcends color or style.

Trends update jeans

"Denim means a lot to people," said Alison Sokolove, a fashion industry analyst and trend forecaster with the New York-based Tobe Report. "It's a way of expressing yourself, a very universal thing. A lot of brands don't want to be associated with the larger-size market, so jeans that fit right and feel good and last mean a lot to people. So it is emotional."

And as the most universal of apparel, the jeans category is being updated faster than other fashion categories can cycle in and out of style. Lycra and other stretchy fabrics have been blended with denim to minimize shrinkage and wrinkling, cashmere blends offer incredible softness and genetically unaltered, pesticide-free cotton styles are an outgrowth of the big organic trend.

"They're constantly searching for that new thing," said Ms. Sokolove, citing likely coming trends such as colored denim and edgier styles from countries such as Japan, Australia, Turkey and Sweden.

With so many styles and variations in denim jeans, fit remains the most important quality for consumers. On Nov. 6, Shopping.com launched a denim-finding feature that allows women to "try on" up to 50 different pairs of jeans with the click of a mouse based on style preferences and 11 algorithmic calculations of body type.

Perhaps more than any other garment, jeans illustrate the cycles of fashion. Like a venerable grandfather clock, the pendulums of jean trends swing from high waist to low, dark wash to light, wide leg to straight, lavish embellishment to simplicity -- back and forth with a hypnotized public buying constantly to stay current.

There is an element of planned obsolescence in fashion. Profit-conscious designers understand that a small but disproportionately influential segment of the market always clamors for the next, the latest, the newest. So they constantly reinvent, drawing on what once was to create what is to come.

Yet, jean trends are more complex. Change is driven by market forces that exert as much influence from the bottom up as from the top down. Rebellious youth cultures that ripped, slashed and painted jeans over the past two generations influenced designers in new directions.

Jeans' popularity on rise

Levi Strauss, who was responsible for bringing jeans to the masses, would be amazed at the jean scene today. The Bavarian immigrant could not have foreseen the evolution and mass appeal of the denim "waist overalls" he and business partner Jacob Davis patented and began manufacturing 133 years ago in San Francisco.

Back then, blue jeans were the unofficial uniform of miners, ranchers, farmers, lumberjacks. They were for men who labored hard. Rebel kids began to wear them in the 1950s, and the baby boomers became the first generation to grow up wearing jeans.

Today, jeans are common in the workplace, often dressed up in business professional ensembles. A recent survey by Cotton Inc. reported that a steadily growing number of women and men -- 67 percent and 70 percent, respectively -- prefer jeans to casual slacks and wear them an average of four days a week.

The average American woman owns 8.3 pairs of jeans today compared with 6.5 pairs a decade ago, according to the Cary, N.C-based trade organization. She pays an average $35.83 per pair, $3.15 more than in 1998.

Similarly, American men are paying an average $2 more per pair than eight years ago and own an average 8.23 pairs, about two pairs more than a decade ago.

Much of that growth can be attributed to increased variety, comfort and durability. Bleached, embroidered and ripped jeans have cycled out, but several other trends have extended their popularity beyond the normal two to three seasons.

One example is the luxury jean, also known as "premium denim." These are meticulously constructed, decadently comfortable versions by high-end designer names such as Michael Kors and Dolce & Gabbana and cult brands like Stitch's and True Religion. Many shoppers are willing to shell out $200, $500, sometimes more than $1,000 for one pair.

In the early '80s, labels such as Gloria Vanderbilt, Calvin Klein and Jordache caused blue jean prices to spike with the advent of "designer jeans," the first wave of pricier denim. And over the past decade, manufacturers have been able to command prices for jeans that no one foresaw.

Observers thought the trend would taper off in a fad-driven industry within a struggling economy.

That hasn't happened.

Yet, the rise and reign of expensive denim hasn't lead to the demise of inexpensive, run-of-the-mill blue jeans, either.

"You don't have to entice people to buy jeans," said Mr. Scott, the South Side store owner. "People are going to buy straight-up workwear jeans, for sure ... Plenty of classic-style blue jeans are going to be bought and sold."

The resurgence this fall of jeans with cigarette-thin legs and a higher waist may be just another option rather than The Next Major Wave.

"It remains to be seen whether the skinny-leg thing might go away after this fall," said James Sullivan, author of the new book, "Jeans: A Cultural History of an American Icon."

"It's definitely going to have some resistance," he predicted. "It's definitely not going to fly off the shelves. It's not the most flattering silhouette. It's a lot easier to wear a low-rise than a high-rise. The fashionistas are going to buy it, but they're going to buy it in very limited ways. This is definitely not something that's going to catch on overnight."

Regardless of how they look, jeans must be comfortable and constructed well to make it in the market.

Take, for example, Ms. Smith's American Eagle jeans. AE was the second most-searched brand in the women's jean category on eBay -- behind Abercrombie & Fitch -- during a two-week snapshot between Sept. 23 and Oct. 6.

In that same time period, 6,197 pairs of women's jeans and 4,239 pairs of men's jeans were bought at the online auction house. On Oct. 6, more than 59,300 items were listed in the women's jeans category -- a testament to the garment's popularity.

But for every pair of jeans sold, tossed or given away, there is another that has earned a permanent place in someone's closet and heart.

Dorothy Michalski, 49, doesn't care that she can no longer fit in the jeans she was wearing when she met her husband on Oct. 26, 1973. She has no intention of getting rid of them.

"I was about 115 pounds ... at the time," recalled Mrs. Michalski, a former Pittsburgh resident who now lives in Simpsonville, S.C. "Since then, I've put on much more weight and had two children. But I won't ever give them away!"