I am looking for simple T-shirts with a slim fit for a slim body type. I'm a little fit but not very muscular. Regular fit T-shirts always tent up on my back and stomach which looks unpleasing. I'd like to find some brands with an ethical production chain who produce high quality clothing which lasts some time. I'm fine with a T-shirt costing up to ~50€ if it's worth it.

Does anyone have some recommendations?