Flannel has a cheap version problem. You know the one: pilled after three washes, hangs like a sack, and the brushing is so aggressive it feels more like carpet than cloth. Most of what’s out there falls into that category, which is why we spent real time separating the ones worth buying from the ones that look fine on a hanger and nothing else. The flannel shirts we’ve pulled together here are the kind that actually improve with wear, that hold their structure after laundering, and that look like a considered choice rather than something you grabbed at a gas station. We’ve been particularly interested in shirts where the weight is right for layering under a waxed jacket or wearing open over a clean white tee. Fit matters too. Boxy is not casual. It’s just boxy. These are cut with enough attention that you could tuck one in and not embarrass yourself.