Flatlocking

Flatlocking is a type of seam construction used primarily in sewing and garment manufacturing. It is characterized by its distinctive appearance, where the raw edges of two fabric pieces are folded and sewn together in such a way that they lie flat against each other. This creates a strong, durable seam that is also comfortable against the skin as there are no raw edges exposed or bulky overlaps.

The process of creating a flatlock seam typically involves a specialized sewing machine, often called a coverstitch or overlock machine with specific flatlock capabilities. The fabric edges are fed into the machine, where they are simultaneously trimmed, overlocked, and then flattened. The needle stitches pass through the seam allowance, securing the edges together and creating a smooth, low-profile finish.

Flatlocking is widely used in various applications. It is common in athletic wear, lingerie, swimwear, and children's clothing due to its comfort and flexibility. The smooth finish prevents chafing and irritation, making it ideal for garments worn close to the body or during physical activity. It is also used in home furnishings, such as bedding and upholstery, where a clean and durable seam is desired. The visual effect of flatlocking can also be a design element, with contrasting threads used to highlight the seam's pattern.