Soft, plush and infinitely comfortable, cashmere is the most classically luxurious garment a man or woman can wear, whether it's a suit, sports jacket, sweater, polo or even a pair of socks. For those keen on surrounding themselves with the finest possible quality, this is hardly news.

But here's an update: cashmere is no longer relegated to the warmer months exclusively. Now, this luxurious fiber is being made into super lightweight sweaters and jackets and often blended with silk and/or cotton for knitted polos and T-shirts at once cool and comfortable. And durable. So says Pier Guerci, president and chief executive officer of Loro Piana USA, the world's largest producer of quality cashmere fabrics and apparel and perhaps the most revered name in Italian fashion.

"From a performance standpoint, even lightweight cashmere can stand up to any other fiber, including wool," says Guerci. "Contrary to popular belief, it doesn't wear out so long as the fabric is properly finished and the garment is well made."

Credit Loro Piana as the first company to turn out cashmere clothing that is virtually seasonless, with certain knits purposefully designed for the dog days of summer. Newest is a collection of tailored sports jackets made of nine ounce worsted cashmere that Guerci insists can be worn 10 months out of the year. Perhaps even more remarkable are Loro Piana's single-ply and two-ply super light weight cashmere and silk knit shirts, which Guerci calls "the ultimate luxury in golf shirts.

"It just doesn't get any better than silk and cashmere for a polo shirt," says Guerci. "From the pleasing soft touch of the fabric against the skin to its super light weight, it's like wearing nothing."

Of course, don't expect to pay lightweight prices for all this luxury; practically anything cashmere is heavy on the wallet, especially if it's made in Italy. For the uninitiated, cashmere has, aptly enough, a regal history - legend has it that the Caesars' togas in ancient Rome were made of the fiber.

The name "cashmere" descends from Kashmir, the wild and mountainous area of India and Pakistan where most cashmere yarn was once spun. The actual fleece comes from the wild goats of Tibet and Outer Mongolia from whom the cashmere fibers are sheared. Interestingly, only the under-down - the soft, down-like hair from the goats' fleece, rather than the coarse, outer hair, is used.

As with the Roman Caesars, cashmere throughout history has always won favor among the noble and wealthy. Empress Eugenie, wife of Napoleon III, popularized cashmere among the French upper classes after having the fiber locally woven into her famous "ring shawl" - so called because the fiber was woven so fine the shawl itself could be drawn through her wedding ring. Fact or fiction? It's anyone's guess.

The former Men's Style Editor at the New York Times Magazine and Fashion News Editor at Gentlemen's Quarterly, Ralph DiGennaro is one of the preeminent voices in fashion and luxury journalism. A graduate of the University of Florida, his writing and styling has also appeared in Esquire, The New Yorker, New York Newsday, Departures, BusinessWeek, Robb Report, Cigar Aficionado and a host of other national magazines.