I have a bunch of light and medium weight Merino wool undershirts from a company called Merino Tech. Great product.I may have made a wardrobe error. I have this wool submariners roll neck jumper. It's Merino wool and very comfortable and while not quite as warm as the equivelant high tech thermal type clothing it has breathability and good themal properties when damp. I highly recommend them. Nice warm neck and hardly any draft. It just feels comfortable.