There are situations in which an informal outfit and even the use of a T-shirt is required. 

In these cases I use Ralph Lauren T-shirts.

Ralph Lauren, from New York, has always offered an unmistakable style. Casual but always elegant, it takes inspiration from the aristocratic Polo. The logo with the classic polo player and the horse can not fail to please as well as being a distinctive sign even for a low budget outfit.

Please note, in this case we are not talking about Polo shirts, so no collar and no buttons.

My T-shirts.

Source of inspiration and credits: https://www.ralphlauren.com/