Flatlock vs GBS Wetsuit Seams: What Is the Difference?

When people see a wetsuit for the first time, they usually notice the color, design, thickness and logo.

Experienced buyers often look somewhere else first: the seams.

A wetsuit is assembled from multiple pieces of material. How those pieces are joined can affect comfort, water entry, manufacturing complexity and the intended use of the finished product.

Two terms frequently encountered in wetsuit manufacturing are Flatlock and GBS.

What Is Flatlock Stitching?

Flatlock is a seam construction designed to create a relatively flat joint between material panels.

One advantage is that the finished seam does not create a large raised ridge against the body.

Flatlock construction is commonly found in certain wetsuits and other water sports garments.

However, the stitching process creates needle penetrations through the material. For this reason, Flatlock should not automatically be treated as the best option when minimizing water entry through seams is the primary objective.

Its suitability depends on the intended product and environment.

What Is GBS?

GBS stands for Glued and Blind Stitched.

In a typical GBS construction, the edges of the material are glued together before blind stitching is applied.

An important characteristic of blind stitching is that the needle is intended not to pass completely through the material in the same way as a conventional through-stitch.

This helps reduce through-holes along the seam.

As a result, GBS is commonly considered for wetsuits where reducing water entry and improving thermal performance are important design considerations.

Is GBS Always Better Than Flatlock?

No.

Manufacturing decisions should not be made simply by choosing the process that sounds more advanced.

Different seam constructions have different costs, production requirements and applications.

For a product intended primarily for relatively warm conditions, the balance between comfort, flexibility, construction and cost may lead to one solution.

For products designed for cooler environments, reducing water entry may become more important.

The intended use should therefore come before the manufacturing method.

Why Does GBS Require Experience?

From the outside, a finished seam looks simple.

Inside the factory, the process can involve edge preparation, adhesive application, alignment, curing and blind stitching.

Stitching too deeply can penetrate the material. Stitching too shallowly can affect seam stability.

Equipment matters, but operator experience and process control matter as well.

What Should OEM Buyers Ask?

Instead of asking only:

“Can your factory make GBS wetsuits?”

A more useful question is:

“Why should my wetsuit use GBS rather than another seam construction?”

A manufacturer should be able to discuss the answer in relation to the intended environment, thickness, product positioning and budget.

Dongguan Yalisi Sporting Goods Co., Ltd. manufactures wetsuits and related water sports products and works with different construction requirements depending on customer specifications.

For buyers developing a private-label wetsuit, understanding why a particular seam is being used can be more valuable than simply seeing “GBS” written on a quotation.