Most wool jerseys are merino wool, which is very soft and non-itchy. I don't like the feel of wool on my skin at all, but I can wear my Rivendell merino jerseys comfortably. They're great in cool to cold weather, and I wore one today when it was probably in the high 70s. It wicked well and felt fine. Haven't tried them on hot days, but they're the traditional material in Europe and a lot of people do wear them. Really, though, they're pretty expensive, and unless you're deeply into The Look, you can be just as comfortable in a cotton T-shirt, which is what I wear most of the time.