A few years ago Uniqlo U made this perfect long sleeve tee- a little boxy, a pretty heavy weight cotton, chest pocket, inexpensive, checked all of the boxes- i wear them all the time. They stopped selling them sadly soon after (of course) and I had only bought like two of them then. Scouring eBay, depop, everywhere regularly though for more to build up the stock, that’s what you do when you find a perfect item, wearing one right now even