7 Things Nobody Tells You Before You Buy a Swimsuit Online

The United States published a women’s sizing standard, PS 42-70, and then withdrew it in 1983. Nothing replaced it with any force of law. ASTM International took over the work, but ASTM standards are voluntary — a brand can label a garment a size 8 because, internally, it feels like an 8.

That is the entire system. It is why you own three swimsuits in three different numbers and all three fit, and why the fourth one, in your usual size, doesn’t.

It is a comparison against a baseline that does not exist. The only thing on a product page that actually carries information is a measurement — centimetres or inches, next to the size, for the part of you that has to fit into it.

If a page says “true to size” and gives you no numbers, it has told you nothing at all.

Look through any swimwear site and count the wet photographs. There are almost none. But fabric under water stretches further, clings differently, and transmits light differently than the same fabric on a dry studio floor.

This is the gap most disappointment falls into. Before you ask what a suit looks like in the photo, ask what it looks like coming out of the sea.

Unlined means there is no second layer of fabric. Unpadded means there are no cups. Neither of those words tells you anything about opacity, and neither tells you anything about lift. A suit can be completely opaque and still give you no lift whatsoever.

Ours is unlined and unpadded. It shapes and smooths; it does not lift. If you want lift, you want underwire — and you should buy a suit that has it, not ours.

Sample sizes cluster tightly, and the garment on the model has usually been pinned at the back to sit perfectly for the camera. If a brand shows you one body, you are looking at one data point and drawing a conclusion about yours.

Look for a brand that shows the same garment on more than one body. If they don’t, write and ask. How a company answers that email tells you most of what you need to know.

This is the point that costs us money to publish, so here is ours in plain English: Flawless collection items are not eligible for return or store credit for size-related reasons. Exchanges require pre-approval, carry a $20 fee, and ship to Sofia, Bulgaria.

We think that is a fair trade for the way the suit is built, and point 7 explains why. But you should know it before you buy, not after — and if that policy is a deal-breaker for you, it is better that you close this page now than find out in three weeks.

If the number is the broken part, the fix is to stop using one. That means a fabric engineered to stretch across a range of bodies, rather than a yarn cut to a fixed measurement and hoped for the best.

Ours is 93% polyamide and 7% elastane, woven in Italy, Oeko-Tex® certified, and made in two sizes: XS–L and XL–3XL. That is not a marketing trick, it is a different fabric specification — and it is also the reason there is no size-based return. There is no wrong size to send back. There are two ranges, and you pick the one your body sits in.

The honest limit: the more the fabric has to stretch on you, the more sheer it sits. If you want more coverage and more hold, take the larger range.