Seam Construction Guide

In wetsuits and other garments, a seam is where two pieces of neoprene or fabric are sewn together. The type of seam used will determine whether the wetsuit has a waterproof seal or not. Two popular types of seams used in our wetsuits are flatlock and blindstitch seams, although many others are available. Flatlock seams create a visible, flat seam on both sides of the garment. While they are not waterproof, they do offer breathability and are commonly used in cool - warm water wetsuits.

On the other hand, blindstitched seams provide a waterproof seal. To create these seams, neoprene panels are butt joint glued together and then stitched with a needle that only penetrates part way through the fabric. This helps prevent water from entering the wetsuit.

In addition to choosing the right seam type, reinforcement techniques can be used to further strengthen and waterproof the seams. Liquid taping and neoprene taping are two of our preferred methods of reinforcement. These techniques help to improve the longevity of the seam and prevent water entry, ensuring that the wearer stays warm in their wetsuit.

Stitch Types

Glued & Blindstitched Seam (GBS)

When it comes to cold water wetsuits, glued and blindstitched seams are the most popular way to keep water out. These seams are designed to prevent excess water from entering the wetsuit, which in turn keeps you warm.

To create glued and blindstitched (GBS) seams, neoprene panels are first cut and then butt joint glued together. Typically, this process is repeated three times because 2 primer coats are required to achieve the strongest adhesion – this is sometimes called triple glued seams. Next, the seams are blind stitched together. Blind stitching is especially important because it adds extra strength to the seam. Rather than fully penetrating the neoprene, the needle only stitches part way through the panel to minimize the risk of water leaking through.

Blindstitching is used on one side of the neoprene on 2mm - 4mm wetsuits and is used on both sides on 5mm+ neoprene (if not additional reinforcement is used such as in our Legend and Session range of wetsuits).

Blindstitching is a sewing technique that can be done with either a single thread or a double thread. Single thread blindstitching uses less thread and punctures the neoprene less, but the seam may be less secure and more prone to running if not finished correctly. Double thread blindstitching, on the other hand, punctures the neoprene more but provides a stronger, more secure seam.

At C-Skins, we use both types of blindstitching, depending on the specific model and what we believe is best for each wetsuit. Our extensive knowledge and experience allow us to determine the optimal stitching technique for each wetsuit, ensuring that our customers receive the highest quality product possible.

Flatlock Seams

For our wetsuits that are designed to be used in cool – warm conditions, flatlock seams are a great durable seam construction while being a much more cost-effective option. These types of seams are commonly found on our cool - warm water summer wetsuits, such as the Element range which are all 3mm
or below. Unlike glued seams, flatlock seams are not waterproof, as the sewing machine needle penetrates both overlapping neoprene panels at the seam during manufacturing.

However, due to their lack of waterproofing, flatlock seams
cannot be used in thicker winter wetsuits, as they allow water through and do not provide protection against cold water flushing into your suit.

Seam Reinforcement

Liquid Taped Seams

One way to reinforce a traditional glued and blind stitched seam is to apply a liquid rubber seal on the outside surface of the wetsuit, creating a sealed outside seam. Our high-end Wired range of wetsuits uses this technique, known as Liquid Taped Seams, to provide an extra layer of protection against water entering the wetsuit. This construction is more durable and long-lasting compared to normal GBS seams. While Liquid Taped Seams may not look as refined as power seams, we have found them to be more durable in the long run.

Xtend Isolation taped seams

Our ReWired wetsuit range boasts a seam construction that is even more durable, thanks to the application of Xtend neoprene tape to reinforce the inside of the GBS seams. This additional layer of protection against water leaks makes the seams more waterproof and durable. Additionally, it helps to prevent skin irritation. Previously, we applied neoprene tape with
normal glue, which could leave glue residue visible on the tape's edge, which could also irritate the skin. However, we have now switched to machine heat-welding the Xtend neoprene tape onto the fabric using a hot melt glue layer, which is a more stable and efficient method than the traditional hand-application of glue.

Critical Seam Reinforcement

Wetsuits endure a lot of wear and tear, they are not always treated with love and care especially when putting them on or taking them off. In order to prevent damage to the seam joints and stress areas, we apply reinforcement patches on the inside to strengthen these vulnerable areas. These patches, known as Critical reinforcement patches, are a strong nylon material that is heat-welded onto the wetsuit, providing increased durability and preventing overstretching of the seam junction which can lead to tearing. These reinforcement patches are typically applied in areas where multiple seams meet or where less flexible material is stitched to a more flexible one, creating an even stress release area.