The It Girl.

"It isn't beauty, so to speak, nor good talk necessarily. It's just 'It'. Some women will stay in a man's memory if they once walk down the street." - Rudyard Kipling

Clara Gordon Bow. The original "It" Girl. 

She got the nickname after appearing as a shopgirl with gumption in the 1927 movie It. And it stuck.

Two decades earlier, in 1904, Rudyard Kipling wrote about "It" (see above), though Elinor Glyn is most often credited with the phrase. 

Whoever gets credit, you know it when you see it or feel it. You likely know if you have it. 

This sweater has the It factor, too. Perhaps you'll add a string of oversized pearls. A pair of tortoise sunnies or a casual tank top layered underneath. (You'll have your own ideas, of course.)

It's never too late to become the next It Girl. 

The It Girl Cardigan (No. 7275). In pure, comfortable cotton. Artfully-finished seams. Four front patch pockets. Crew neck collar. Faux mother-of-pearl buttons. Wrist-length sleeves. Falls at hip. Looks devastatingly good over a dress or skirt or trousers. Imported.