Sullen Flannels now come in 6 different styles, Standard 100% Cotton, "Special Blend" Cotton/Poly Blend, Muffin Stuffin quilted flannels, Thermal lined "Waffles", "Butter" Sherpas, and 1 Ton Ultra-Heavyweight flannel, so they can be worn in all types of weather. The lightweight flannels are perfect year-round but they won't protect you in really cold weather, they can be worn in the summer at night or inside and are perfect for those times you have to dress up but don't want to. Our Standard weight flannels are really meant for winter they are just heavy enough to keep you warm but not too heavy to overheat. Our Heavyweight flannels are like a blanket that you wear, perfect for warm weather they are the warmest flannels we make and are built for comfort. We build all flannels from scratch with the color pallet for the season so they are meant to be worn with the shirts, hats, and accessories from that year.