There's this slight contradiction that exists with clothing: we're encouraged to wear bras and underwear underneath them, but we're also encouraged to hide the fact that we're wearing bras and underwear underneath them. Cue the best seamless bras that won't show up underneath clothing. Personally, I don't particularly care if people can see my VPL (a.k.a. visible panty line) or bra indentations, but lots of people would much rather hide them. If you're one of 'em, don't worry — you've got options.
A bra fitting expert once told me that t-shirt bras are the most popular style because people love that they don't show up underneath tight or lighter-colored clothing. That said, this same expert also said that seamless options (like t-shirt bras) don't always offer the most support, which is why being choosy is important.
A seamless bra is one that doesn't have seams running through the cups, and since more stitching often means more shaping, it's important to do your research when it comes to this type of thing. The review section is going to be your best friend here, because if a bra offers loads of support and comfort inside the shirt as well as a sleek, smooth look outside of it, you better believe that people are going to rave about it. Check out these incredibly-rated seamless bras here.