The Edit · Underpinnings
What to wear underneath.
The dress gets all the attention and the layer under it decides whether the dress works. Here's the under-question answered garment by garment, in the order people actually hit it: backless, sheer, white, fitted, strapless. Plus the two places the money genuinely buys something, and the many where it doesn't.
Under a backless dress
Stop hunting for a bra that disappears and change what the garment is doing. A low-back bodysuit ends where the dress ends and smooths everything between, which is a different and better job than a strap trying to hide. The Margo lace long-sleeve bodysuit (around $149) is the version worth owning: it reads as a garment in its own right, so if a sliver shows at the shoulder nothing has gone wrong.
When the back is cut below the waist there is no clever answer, only adhesive cups. They hold if the skin is clean and bare of lotion, and they fail if it isn't, which is the whole trick and the reason most people think they don't work.
Under something sheer
Sheer fabric doesn't conceal underwear, so the underwear has to look chosen. This is the one case where the layer underneath is meant to be seen, and the failure is always the same: a beige moulded cup doing a poor impression of invisible. Put something deliberate under there instead. A Champagne embroidered triangle bra (about $69) under a black chiffon blouse reads as styling. The same blouse over a T-shirt bra reads as an accident.
The rule is contrast on purpose or no contrast at all. Match the tone exactly or oppose it completely; the near-misses are what look cheap.
Under white trousers
Never white. White under white creates a bright edge the light catches, while a tone close to your own skin genuinely disappears because there's no contrast to find. Buy the shade that looks faintly wrong on the hanger.
Edges matter as much as colour. A high-waist thong (around $23) beats a fuller brief under anything fitted, because the line you see comes from elastic sitting mid-hip where the fabric pulls tightest. Sit above that point and there's nothing to print through.
Under a strapless neckline
The band does all the work, and this is where cheap lingerie loses. A strapless bra with a tired band migrates upward all evening, which is the thing everyone remembers and nobody wants to be managing during dinner. The Charlotte bandeau (about $78) holds because the band is built to, not because of what's happening at the cup.
For a structured bodice, skip the bra entirely. A bustier (around $139) supports through the whole torso rather than one strip of elastic, and under a corseted dress it's the only thing that doesn't fight the shape the dress is already making.
Under anything fitted
Seamless, or nothing. Bodycon jersey and fine knits show every hem, so laser-cut edges are doing more for the outfit than any amount of shapewear. A seamless balconette (about $54) gives shape without a seam to print through.
Shapewear is worth it only when it runs the full length of the garment. Half-length smoothing swaps one visible line for another, slightly higher up, and you've solved nothing.
Where the money is actually worth it
Two places, and they're both structural. Bras, because the band is the entire support system and a well-made one still holds after a year where a cheap one is finished in three months. And bodysuits and bustiers, because they're garments doing a garment's job, not a layer hiding under one. Everyday briefs are where you spend nothing at all; nobody has ever been let down by an inexpensive brief.
The test isn't the price on the label, it's whether the piece is holding a shape. If it is, buy well. If it's just covering, buy cheap and buy often.
Questions, answered
What do you wear under a backless dress?
A low-back bodysuit or a stick-on cup, and nothing that needs a band. The instinct is to hunt for a bra that disappears, but the better move is to change what the garment is doing: a long-line bodysuit smooths the whole torso and ends where the dress does. If the back is cut lower than the waist, adhesive cups are the only honest answer, and they hold far better on skin that's been washed and left bare of lotion.
What bra do you wear under a sheer top?
A deliberate one. Sheer fabric doesn't hide underwear, so the underwear has to look like it was chosen: an embroidered triangle or a balconette in a colour that answers the top rather than apologising to it. The failure mode is a beige T-shirt bra doing a bad job of being invisible. A black lace triangle under a black chiffon blouse reads as styling; the same blouse over a nude moulded cup reads as an accident.
What colour underwear is actually invisible under white?
Your own skin tone, not white. White under white is the single most common mistake — it creates a bright edge that shows through, while a tone close to your skin disappears completely because there's no contrast for the light to catch. Buy the shade that looks wrong on the hanger. Seamless or laser-cut edges matter as much as the colour under anything light or fitted.
How do you stop underwear lines under fitted clothes?
Go seamless, or go higher. Laser-cut edges and a high-waist thong both beat a fuller brief with a hem, because the line comes from the elastic edge sitting mid-thigh or mid-hip where the fabric is tightest. A high-waist cut sits above the widest point and vanishes. Shapewear helps clingy jersey, but it introduces its own edges unless it runs the full length of the garment.
Is expensive lingerie worth the money?
For the pieces that do structural work, yes; for the rest, not really. A well-made bra holds its shape through a year of wear where a cheap one loses its band in three months, and the band is the entire support system. Bodysuits and bustiers earn their price the same way, because they're doing the job of a garment rather than a layer. Everyday briefs are the place to spend nothing.
Working backwards from an occasion instead? The date-night guide and the September wedding-guest guide both start with the dress, and every dress in them lands back on this page.