Underwear vs. Swimsuits That Fit Like Underwear^®: What's the Difference?

If you've ever put on your favorite seamless no-show underwear and thought, "Why can't swimsuits fit like this?," that's exactly why we created onewith.

We loved the smooth, flattering fit of seamless underwear: no digging, no bulky seams, and no visible lines. It's the kind of comfort traditional swimwear could never offer.

So we designed swimwear that fits like underwear, without the ~risks~ of actually wearing underwear in the water.

Can You Swim in Seamless Underwear?

Technically, yes. But seamless underwear wasn't designed for swimming.

Underwear isn't designed to withstand chlorine, saltwater, sunscreen, and repeated swims. They can lose their shape faster, stay wet longer, and simply doesn't offer the performance features you need in a swimsuit.

Most seamless underwear is made from a single layer of lightweight fabric. When wet, it can become more transparent and may not provide the coverage you want at the beach or pool. And, it's not gonna stay in place. A wave, dive, or swim can easily cause it to shift or bunch.

How Is onewith Different?

While onewith swimwear has the same smooth look of seamless underwear that we all know and love, it's crafted differently. 

Our beyond seamless swimsuits are made from two layers of swim fabric bonded together, creating smooth, lay-flat, raw-cut edges, without the bulky seams found in traditional swimwear.

The result is the comfort of your favorite no-show underwear with the performance of real swimwear.

Is onewith Thinner Than a Traditional Swimsuit?

Nope! People often think that our swim has a thinner appearance because of how smooth it is on the body (our swim fits like a second-skin!). Because our swim is bonded instead of sewn, it can appear thinner and smoother than traditional swimwear, but it's made with the same amount of swim fabric you'd expect from a quality swimsuit.

The difference isn't less material; it's a more comfortable swimsuit construction.

Is It More Likely to Be See-Through or Cause 🐫?

Nope! onewith swimwear is made from two layers of swim fabric, just like traditional swimwear. It isn't any more prone to being see-through than a standard swimsuit, nor is it any more prone to 🐫. If that's a concern, we always recommend opting for a darker color or pattern. 

When you're wearing the correct size, the suit is designed to provide a flattering, secure fit without the squeezing and digging caused by traditional seams.

How Does It Stay in Place?

Every onewith swim that fits like undies style features a flexible inner grip strip along the edges of the flattering bathing suit.

This hidden inner grip strip helps keep your swimsuit securely in place both in and out of the water, so you can swim, lounge, and move with confidence.

The Bottom Line

onewith was created to solve a problem: swimsuits should be just as comfortable as your favorite seamless underwear.

By combining patented bonded swim construction, double-layer swim fabric, and a stay-put inner grip strip, we've created swimwear that delivers the comfort of seamless underwear with the coverage, security, and performance of a true swimsuit. That's what makes onewith different.

Ready to experience the difference for yourself? Shop our collection of better than seamless swimsuits here. Be sure to follow us on IG for all updates in the world of swim that fits like undies!