We Were Skeptical of One-Size Swimsuits. Here’s What Worked.

Popcorn suits defy the norms of swimwear. In contrast to suits that come in sizes small, medium, and so on, popcorn suits come in one size, sometimes two. And though we refer to these suits as “one-size-fits-all,” there are limits. It’s really more like “one-size-fits-many.”

Our official popcorn pick, the Youswim Aplomb One-Piece, comes in two sizes: Stretch I, for sizes 2 to 12, and Stretch II, for sizes 14 to 24. The Hunza G Pamela suit, which is featured in the guide as a suit worth considering, comes in just one size, for sizes 2 to 12.

This textured suit comes in just two sizes, yet, remarkably, it expands to fit a wide range of bodies (from size 2 to 24). It’s made from an impressively stretchy, comfortable crinkle material that gently hugs your shape, but it doesn’t offer much compression.

We loved this textured suit with thin straps, a high-cut leg opening, and a substantial, marvelously stretchy popcorn fabric. It comes in just one size (which fits sizes 2 to 12), and it’s pricier than our Youswim pick. It’s also more compressive than the Youswim suit, but it offers less backside coverage.

The crinkles are what make these suits work, since they hide more fabric in plain sight. When you stretch a popcorn suit, you see the tightly bound crinkles start to expand, allowing the suit to cover more surface area. And in our swim tests, these suits didn’t lose their shape or snappiness; instead they maintained their compression when wet and through multiple wears.

Due to their thickness and texture, these suits look quite different on the contours of the body, almost camouflaging the lumps and bumps that traditional smooth suits may highlight, Zoe said. One drawback of this crinkle fabric, though, is the slow drying time, which is something to consider for swimsuits.

Also, these suits notably lack side seams. So one-size-suits can mold to fit different sizes and shapes, and the stretch of the fabric ensures the swimsuit holds its structure even without the seams.

The big difference between our two picks is the fabric used. Youswim’s patented fabric is called Versoform, which is made of 88% nylon and 12% elastane. Hunza G’s patented Original Crinkle fabric uses 97% polyamide (an umbrella term that includes nylon and other synthetic materials) and 3% elastane.

The Youswim suit’s higher elastane content is probably why our testers found it more flexible than the Hunza G suit — for better or for worse, depending on one’s preference. The Youswim suit isn’t incredibly compressive, so those who want to feel “held in” by their swimwear may prefer the Hunza G suit. But overall, the Youswim suit’s fabric is cushiony, and Zoe described it as a “wonderful spongey hug.”

That lack of support is also a downside for some. You’ll also notice these suits lack built-in bras and cups. This design accommodates a range of bust sizes, but there is also less support in the chest area than you get with a traditional padded swimsuit. Still, one tester with a 42DD cup size found the Youswim suit surprisingly supportive. “For being so comfortable, it does a pretty good job of basic support for the chest,” they said. Other testers found the closer-hugging, compressive fit of the Hunza G suit to be more supportive.