Leave it to Ralph Lauren to turn an old Celtic knit into a fashion icon. The cabled Aran sweater was created at the turn of the last century by Irish craftsmen, who knew (quite literally) how to spin a good yarn out of scratchy lamb’s wool. In the early eighties, Ralph added his Midas touch, creating an All-American look and a modern, slim fit—all in 100 percent cashmere. Almost instantly, his refined twist became a staple for travelers and a classic carry-on, equally at home in Aspen, on the streets of New York, or at 35,000 feet. Over the years it has been rendered in cardigans, crew necks, and even sweater coats. This season the look is extra-long, with the cables angled around a deep V-neck. Irish lore says that the pattern is a symbol of luck—no wonder it never goes out of style.