We have a standard weight solid-color flannel and a double-nap flannel. Both are great for bopping around the house or for keeping you warm when out and about in crummy weather.
What is a double-nap flannel? All flannels start as a piece of fabric that is brushed on at least one surface. This brushing action gives the fabric this soft feel to it. Double-nap flannels are especially thick fabric that is brushed on both the inside and outside surfaces. Very nice fabric for boxers though somewhat thick.