Flatseamed

Flatseamed refers to a seam construction designed to lie flat against the fabric, producing minimal bulk and reduced irritation against the skin. It is commonly used in knit garments and performance wear, where stretch and comfort are important. The term can describe both the technique and the finished appearance of the seam.

Construction and methods

Flatseaming is typically achieved with a flatlock or specialized overlock stitching that joins two fabric edges without folding the seam allowances to one side. The edges are aligned and fed into a machine so that the stitch interlocks around the fabric edge, locking the plies together. The result is a seam that sits flat on both sides of the garment, often with a smooth outside surface and a slightly reinforced inside edge. Depending on equipment and fabric, a flatseamed construction may use a dedicated flatlock machine or a serger/overlock with a flatlock setting, and can be finished with additional topstitching or cover stitches for durability or aesthetics.

Variants and considerations

Two common variants are the flatlock seam, which emphasizes minimal bulk and a flat exterior, and double-stitched flat seams that add a second line of stitching for extra strength. Flatseams are particularly suited to stretchy knits, woven innovations, and technical fabrics used in activewear, swimwear, and undergarments. They require carefully prepared fabric edges and compatible knit fabrics to prevent edge curling or seam instability.

Applications

Flatseamed construction is favored in sportswear, swimwear, and intimate apparel where comfort, freedom of movement, and reduced chafing are priorities. It is also used in some athletic footwear linings and performance gear.

See also

Flatlock stitch, overlock, cover stitch.