This is awesome. It's super-soft, totally non-itchy, and keeps me ridiculously warm. I've used it as both my next-to-skin layer, as well as a second layer over a lighter-weight baselayer. I can comfortably get a SmartWool Microweight longsleeve baselayer on underneath, without feeling restricted in movement. However, if you're needing to put a Midweight layer on underneath it, I'd suggest buying a size larger than you normally would. My normal size (small) is a little snug with multiple (thicker) layers on underneath. Overall, though, it's fantastic, and I definitely want to buy another one!