Most cotton long sleeves look fine on day one and start lying about themselves shortly after. A few washes in and the collar has lost its shape, the fabric has gone thin in the wrong places, and what felt like a considered purchase now looks like an afterthought. That failure is almost always a construction problem, not a care problem. The wrong cotton weight, cut too generously to hide poor patterning, finished without enough attention to the collar and cuffs. We’ve been looking specifically at options that earn their place as a wardrobe staple rather than just filling that role temporarily. The pieces in here work as a base layer under a shirt, hold their own with a good chino, and still look decent after a year of regular wear. Fabric weight, collar structure, and sleeve length that actually reaches the wrist. Those are the things we checked. These are the ones that passed.