By Jonesea

When choosing a wetsuit, it's important to understand its construction. Knowing the construction techniques used in a wetsuit can aid in selecting the best style for your needs.

Wetsuit construction typically involves the use of two main types of seams: blindstitch and flatlock. Both methods have their own unique characteristics and benefits that make them suitable for different types of wetsuits.

What is a Blind stitch seam?

Blindstitch seams are a popular method used in wetsuit construction, as they provide a durable and warm seal that keeps water out. The technique involves gluing the two ends of the material together and then stitching them with a single hook needle. The needle only penetrates halfway through the material, ensuring that no water enters the seam.

This method is known for its strength and durability, making it a great choice for colder water temperatures or for wetsuits that will be used in more demanding conditions. Additionally, the use of a specialized thread in the stitching process, such as premium bonded nylon, can also help to increase the durability and overall performance of the wetsuit.

What is a Flat lock seam?

Flatlock seams are another popular method used in wetsuit construction, typically used in warmer water temperatures or for wetsuits that are designed for less demanding conditions. The Flatlock process is a faster technique of sewing resulting in a lower pricepoint product. Flatlock seams are created by sewing two pieces of material together using multiple needles. The needles penetrate through both layers of material, allowing water to flow in and out of the suit through the seam.

The seams are usually wider than blindstitch seams, which is an easy way to identify a flatlock seam. The thread that I use for flatlock seams is a hemp based thread which is breathable, moisture-wicking, anti-bacterial, and naturally hypoallergenic which helps to provide added comfort and breathability to the wetsuit.

Blind StitcH Vs. Flat Lock


Timeframe: 5-6 hours

Uses a cut - glue - sew - tape - process.

Water tight seam



Timeframe: 1-2 hours

Uses a cut - sew process.

Not water tight


Both blindstitch and flatlock seams are good options for wetsuit construction, but it's important to understand your specific needs and preferences. Factors such as the water temperatures you'll be using the wetsuit in, the level of activity and usage, the longevity and quality you are looking for, and your budget will all play a role in determining which type of seam is best for you.

Both options have their own unique characteristics and benefits, and it ultimately comes down to personal preference and the intended use of the wetsuit.

I currently offer all of my wetsuit styles with a blindstitch seam construction. I believe this method provides the best all-around performance and durability. However, I am planning to introduce flatlock style of suits for the summer of 2023.