Clearly the hemline index isn’t the only trend that’s out of whack with the economic crisis. More proof that fashion is defying the downturn emerged at last night’s book launch for Vanity Fair and USA Network’s exhibit “Character Project”: Christian Siriano revealed that his sales have doubled since last season — and it’s not just thanks to his fetish heels for Payless. Propelled by some strategic price-slashing, even sale-happy stores like Intermix are expanding Siriano’s reach, bringing his line into more and more locations. “The good thing about my company is it’s really small and it’s growing, and we didn’t have to lay off a bunch of employees because I don’t have a bunch of employees,” he explained. “It’s crazy to think. You’re like, ‘Oh my God, you doubled sales in this economy?!’ But because last season was my first real season, my sales were small because I was so new. We had a handful of really good stores, and now this season we have ten great new stores.” He was tight-lipped about which new stores he’s selling in, but said they were “big.” Somewhere, Kenley is crying.