Alpaca is totally the new cashmere. People who had never given alpaca a thought just a year ago are noticing its growing popularity, as the fiber starts popping up on more and more fabric content labels. Most of these products reveal just small percentages of alpaca, but demonstrate designers' and retailers' desire to advertise alpaca content and include the word in their product names. This practice mimics the fashion industry's love affair with cashmere in past decades, with sweaters and ac …