The Ultimate Guide to Manufacturing Custom GBS (Glued & Blind Stitched) Wetsuits

Have you ever received a production sample of your brand's new wetsuit, held the seams up to the light, and seen tiny pinpricks of daylight shining through? Or worse, have you received feedback from your first customers that their "cold water" suit is leaking like a sieve?

For a watersports brand, this is a catastrophic failure. The single most important job of a temperate or cold-water wetsuit is to keep the user warm, and that is impossible if the seams are not waterproof. A leaky seam isn't just a defect; it's a fundamental flaw that undermines your product's entire purpose and your brand's credibility.

So, what is the essential technology that separates a truly warm, sealed wetsuit from a leaky, low-quality one? The answer lies in the construction of its seams, and the gold standard for performance is known as GBS, or Glued and Blind Stitched.

But what does GBS actually mean? Why is it so much better than a standard flatlock stitch? And how do you, as a brand or supplier, ensure you are specifying and buying a wetsuit with a genuine, high-quality GBS construction?

As a direct manufacturer and supplier of custom neoprene wetsuits, we believe that the seam is the unsung hero of a great wetsuit. It's a detail that requires precision, expertise, and the right technology. This guide is designed to give you a manufacturer's insight into this critical process, so you can source your next wetsuit line with confidence.

If you're ready to build a wetsuit that is truly sealed for performance, let's break down the technology. For a technical consultation or to start your custom GBS wetsuit project, our lead developer, Kevin, is available at kevin@neoprenecustom.com.

What Exactly is a Glued & Blind Stitched (GBS) Seam?

A GBS seam is not just a type of stitch; it's a multi-step construction process designed to create a seam that is both incredibly strong and, most importantly, waterproof.

Let's break down the two key steps:

Step 1: The "Glued" Foundation

Before any stitching happens, the edges of the two neoprene panels that will be joined are precisely cut. A specialized, highly durable contact cement is then applied to both edges.

The edges are allowed to become tacky and are then pressed together under pressure. This creates a powerful, flexible, and completely waterproof bond. At this stage, the two panels are already a single, sealed piece. If you were to stop here, the seam would be waterproof, but it wouldn't be strong enough to withstand the stresses of surfing or diving.

Step 2: The "Blind Stitched" Reinforcement

This is where the magic happens. A "blind stitch" is a special type of stitch that does not go all the way through the neoprene.

A highly specialized sewing machine with a curved needle is used. The needle enters the surface of the neoprene, travels through about half the thickness of the foam, and then exits on the same side. It never punctures the opposite surface. The machine then repeats this process, creating a strong, interlocking stitch that holds the glued seam together without creating any holes that could let water in.

The result is the best of both worlds: the waterproof integrity of a glued bond combined with the strength and durability of a stitched seam.

Why is GBS the Minimum Standard for a Performance Wetsuit?

If your brand is creating a wetsuit for anything other than very warm, tropical water, a GBS seam is not a luxury feature; it is an absolute necessity. Here's why:

1. It's All About Warmth: The primary purpose of a wetsuit is to trap a thin layer of water between the suit and your skin, which your body then heats up. A leaky seam constantly "flushes" this warm water out and lets cold water in, making it impossible to stay warm. A GBS seam prevents this flushing, keeping you dramatically warmer for longer.

2. Superior Durability: The combination of glue and stitching creates a seam that is far more durable than a stitch-only seam. The glue provides a continuous bond that distributes stress, while the stitching provides the raw tensile strength.

3. Enhanced Flexibility: Because the blind stitch only penetrates halfway, it allows the seam to stretch more naturally with the neoprene compared to a more restrictive stitch that goes all the way through.

The Seam Hierarchy: How GBS Compares to the Alternatives

To fully appreciate the value of GBS, it's important to understand where it sits in the hierarchy of wetsuit seam construction.

Below GBS: Flatlock Stitching

This is the most basic seam, found on entry-level and warm-water suits. The panels are laid edge-to-edge and stitched together. The needle goes all the way through the neoprene, creating thousands of tiny holes.

• Is it waterproof? No. It is a "breathable" seam that leaks water freely.

• Why use it? It's strong, comfortable (lies flat), and very cheap to produce.

• Verdict: Only suitable for tropical water (22°C+ / 72°F+) where warmth is not the primary concern.

The GBS Standard

As we've discussed, this is the waterproof standard for performance.

• Is it waterproof? Yes.

• Why use it? It provides the best balance of waterproof performance, durability, and cost for the vast majority of temperate and cold-water wetsuits.

• Verdict: The minimum requirement for any wetsuit intended for water below 22°C / 72°F.

Above GBS: Taped and Liquid Sealed Seams

These are enhancements applied on top of a GBS seam to take its performance to the next level.

• Internal Taping: A flexible neoprene tape is glued over the inside of the GBS seam. This adds another layer of waterproofing, reinforces the seam against stretching, and feels smoother against the skin.

• External Liquid Seal: A bead of flexible urethane is applied to the outside of the GBS seam. This creates an impenetrable outer barrier, making the seam 100% waterproof and incredibly resistant to abrasion.

Verdict: Taping and liquid sealing are premium features found on high-end and extreme cold-water wetsuits. They represent the pinnacle of warmth and durability.

As a custom wetsuit manufacturer, we offer this full spectrum of seam technologies. We can help you buy the right neoprene fabric and specify the ideal construction to create a product perfectly matched to your brand's target market and price point. Explore our capabilities at https://source.neoprenecustom.com.

How to Buy & Specify a Custom GBS Wetsuit

When you are ready to source your custom wetsuit line, providing a clear technical specification to your manufacturer is crucial. This ensures you get an accurate quote and a product that meets your performance standards.

Your specification should include:

1. Seam Construction: Be explicit. "All seams to be Glued & Blind Stitched (GBS)." If you require taping, specify it: "GBS with 100% internal neoprene taping."

2. Core Neoprene Fabric: The best seam in the world can't save a bad suit. Specify the foam grade (SBR, SCR, or 100% CR) and the thickness (e.g., 4/3mm). For a performance GBS suit, a high-grade SCR or 100% CR is strongly recommended.

3. Lamination & Finishes: Specify the interior and exterior fabrics (e.g., "High-stretch nylon jersey interior and exterior") and any special panels like a "Mesh Skin windproof chest plate."

4. Zipper & Entry System: A GBS suit should be paired with a high-quality entry system, like a Chest Zip, to minimize flushing. Insist on a reliable zipper brand like YKK.

5. Request a Sample: Never place a bulk order without first approving a full pre-production sample. Test the seams, check the fit, and verify every detail. This "golden sample" is your contract for quality.

Conclusion: The Seam is Your Signature of Quality

For any brand serious about watersports, the choice to use GBS construction is a fundamental statement of quality. It tells your customers that you understand their need for warmth and that you have invested in the proper technology to deliver it.

A leaky flatlock seam on a 4/3mm wetsuit is a design flaw. A perfectly executed GBS seam is a mark of a professional, performance-oriented brand.

Don't let your customers' sessions be cut short by the cold. By partnering with a manufacturer who has mastered the art and science of the GBS seam, you are not just buying a wetsuit; you are investing in your brand's reputation for performance and reliability.

Ready to buy or build a line of custom GBS wetsuits that are sealed for warmth and built to last? Let's start the conversation. Contact our wetsuit development team, led by Kevin, at kevin@neoprenecustom.com.

FAQ: Your GBS Wetsuit Manufacturing Questions Answered

Q: How much more does a GBS wetsuit cost compared to a flatlock suit?
A: The GBS process is significantly more labor-intensive and requires more skilled technicians and specialized machinery. As a result, a GBS suit will have a higher manufacturing cost than an identical flatlock suit. However, this cost is essential to create a product that is functional in temperate or cold water.

Q: Can GBS seams leak or fail over time?
A: A well-constructed GBS seam is very durable. However, over years of heavy use, stretching, and exposure to sun and salt, the glue can eventually degrade. This is why high-end suits add internal taping or external liquid seals—to dramatically extend the waterproof lifespan of the seam.

Q: Is GBS necessary for a summer wetsuit (e.g., a 2mm shorty)?
A: It is not strictly necessary. For very warm water, a breathable flatlock seam can be more comfortable and is much more cost-effective to produce. GBS becomes the standard when the water temperature drops and warmth becomes the primary goal.

Q: What is the difference between a blind stitch and a normal stitch?
A: A normal stitch (like on a t-shirt) uses a needle that passes completely through both layers of fabric to lock the thread. A blind stitch uses a special curved needle that is designed to catch only the top layer of the material without punching all the way through to the other side, thus creating no holes in the sealed barrier.