Yet another thing Mama was right about.

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For many Southern women, summer’s unofficial dress code involves wearing a whole lot of white: White shoes for church, white jeans for play, and little white dresses for every occasion in between. While the little white dress can’t be beat for its effortlessly breezy, endlessly stylish appeal, the summertime wardrobe staple comes with its own perils, especially when the material is lightweight and nearly transparent. It’s an age-old dilemma, and one with a solution that may be a little less obvious than one would expect: what to wear underneath.

Of course, some underwear options are quite obviously not a good match for your favorite flirty white frock: Black underwear, for instance, or a brightly colored bra, will show right through, no matter how thick the dress’s material. And if we’re being honest, who’s going to wear a thick dress—even a white one—for any amount of time given our hot, humid summer days? Patterns also prove tricky under white jeans or white dresses, so it’s best to skip those altogether.

Perhaps a little less intuitive, the tricky reality of wearing white underwear with white dresses: While white undergarments might seem like a winning move, they actually appear more opaque under white fabric and therefore are easily visible.

I almost learned the no-white-under-white lesson the hard way in middle school. Thankfully, my mama caught me on the way out the door and introduced me to the old-faithful rule that’s saved me plenty of warm-weather wardrobe snafus since: When it comes to wearing white clothes, it’s best to stick to nude underwear. Unlike their bright white counterparts, which seem to pop under other white fabrics, nude undergarments disappear. Voila!

But the color of your underwear isn’t the only thing that matters: In order to avoid unsightly lines and wrinkles, especially in dresses that more closely skim your body or in curve-hugging jeans, you’ll want to stick to nude underwear without a lot of texture. In other words, save the lace for looser-fitting pieces, and choose seamless nude undergarments for a smoother look. Bonus: seamless bras and underwear are typically a lot softer and more comfortable anyway. We’ll call it a win-win.

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Is it ever okay to wear black or white to a wedding? Share your thoughts with us in the comments.