Men, you may have noticed that all of your swim trunks have a layer of mesh inside. If you’ve ever wondered why it exists or questioned whether you’re supposed to wear underwear with it, you’re definitely not alone.
Mesh liners have been a swimwear staple for decades, and they’re more functional than they might appear. They can provide support, improve coverage, help water drain quickly, and eliminate the need for another layer underneath.
Still, not every liner is the same, which explains why some disappear comfortably while others spend the entire beach day making their presence known. Learn about liners and summer fashion in this guide.
The Main Reason Is Built-In Support
The primary purpose of a mesh liner is surprisingly straightforward: support. Because swim trunks tend to be loose and lightweight, they don’t naturally provide the same security as fitted underwear. The liner essentially acts as a built-in pair of briefs.
When shopping for swim trunks for men, you’ll notice that liner designs can vary considerably. Traditional trunks might feature loose mesh, while newer styles may use stretchy, fitted materials. Either way, the goal is to keep everything comfortably in place while you swim, walk the boardwalk, or attempt an overly ambitious beach volleyball dive.
Mesh Liners Help With Coverage, Too
Water has an impressive ability to make perfectly normal clothing suddenly reveal more than expected. Once swim trunks get soaked, their outer fabric may cling to the body or become slightly transparent.
A liner provides an additional layer of coverage between you and the wet material. That extra barrier can make climbing out of the pool or ocean feel considerably less revealing, particularly with lighter-colored or thinner swimwear.
Why Mesh Instead of a Different Fabric?
Mesh is used because it’s lightweight and allows water to move through it easily. Imagine lining swim trunks with thick cotton. They’d soak up water, become heavy, and take forever to dry.
The small openings in the mesh allow water to drain while also encouraging airflow. This helps trunks feel lighter after swimming and lets them dry faster once you’re back on land.
Do You Need To Wear Underwear With Lined Swim Trunks?
Usually, no. The liner is specifically designed to replace underwear while you’re swimming. Regular cotton underwear tends to absorb water, so it can become heavy, bunch up, and stay damp long after your trunks have started drying. That combination isn’t exactly a recipe for comfort.
However, personal preference matters. If the liner fits well and provides enough support, an extra layer generally isn’t necessary. If it doesn’t, choosing a different liner style may be more comfortable than doubling up.
Why Do Some Mesh Liners Feel Uncomfortable?
For something designed to improve comfort, mesh liners can occasionally accomplish the exact opposite. Cheap or poorly fitted liners may rub against the skin, dig into the legs, or create irritation after hours of walking around in wet swimwear.
Fit is often the culprit. A liner that’s too tight can pinch, while one that’s too loose may bunch or shift. Rough materials and bulky seams can also cause chafing, especially during active beach days. A good liner should provide support without constantly reminding you that it’s there.
Traditional Mesh vs. Modern Compression Liners
The classic swim trunk liner looks somewhat like a pair of lightweight mesh briefs. It’s simple, breathable, and effective, but it isn’t your only option anymore.
Many modern trunks feature compression-style liners. These liners fit closer to the body and may offer additional support while reducing skin-on-skin rubbing. They can be especially appealing for activities like paddleboarding, beach volleyball, or running along the shore.
Neither design is automatically better. Some people love the barely-there feeling of traditional mesh, while others prefer the secure fit of compression liners. Comfort ultimately comes down to personal preference.
Can You Cut Out the Mesh Liner?
If your liner feels like a tiny fishing net plotting against you, grabbing scissors might seem tempting. Removing it can make uncomfortable trunks more wearable, but there are trade-offs.
Without the liner, you’ll lose some support and coverage. If you decide to remove it, cut carefully around the seams without damaging the outer fabric. You can then wear quick-drying compression shorts underneath if additional support is needed. Better yet, consider buying linerless trunks next time rather than performing swimwear surgery.
The Mesh Has a Purpose
That mysterious mesh isn’t there by accident. It provides support, adds coverage, promotes drainage, and can eliminate the need for underwear.
Of course, the best liner is one you barely notice. Whether you prefer classic mesh, stretchy compression fabric, or no liner at all, choose trunks that keep you comfortable enough to focus on swimming, not on what’s happening underneath them.
