What happened to nice cotton shirts that show off the shoulder and arms but hide the fact you probably have bit of a tummy? I'm convinced all these weird fiber shirts are a conspiracy by dudes who have big pecks and flat abs but no arm muscles.
Plus all those microfiber shirts make it feel like I have a wet silk blanket on me.
I would recommend finding heavyweight cotton shirts, they're often sold as workwear but they're just plain shirts with thicker material. I found the Dickies and Gildan ones pretty solid but a ton of places make em.
Discovered them incidentally in a quest to avoid constantly putting holes in them at work, but they do help hide a couple pounds much better than regular shirts (and also prevent showing nips through if that's a problem for you).
I wear those thick Carhartt cotton shirts all the time. The material is really thick so it lasts for a lot of washes and also stops my nips from poking though the shirt. Poggers