Uniqlo's HEATTECH line was created to offer thin yet warm layering pieces that are durable and hold their shape. This is all great, but what piqued our interest was the price point ($10-15) and a foil-backed package that looks like it should hold an astronaut's dinner. We're not big on synthetic fibres around here, but the long-sleeve T-shirt we checked out is really soft and very nice. You'd never know it's a labratory concoction of acrylic, polyester, viscose and elastane. It's also really thin, but they weren't kidding about the heat retention. We're ordering more before they raise the price.