Seam Performance and Problems

A seam decides both how a garment looks and how long it lasts, so it drives saleability and longevity directly. Seam quality depends on the interplay of fabric, thread, and needle; the chosen stitch and seam type; the sewing and pressing equipment; material handling; and how well the machinery is run and maintained. Here is what "good performance" means, and the six problems that signal it has failed.

Part I: Seam performance

Performance is the elasticity, strength, and flexibility of a seam, all tied to fabric, stitch/seam type, thread type and size, and stitch density (SPI).

Elasticity

Two components: elongation (how far a seam stretches without breaking) and recovery (its return to original length once stress is removed). Garments like leotards and swimsuits need high elongation and recovery in both fabric and seam to perform.

Strength

The key to durability, measured by resistance to pulling force and abrasion. Seam tenacity is the force needed to break the fabric or the weakest stitch in the seam.

Flexibility

Affects drape, comfort, and abrasion resistance. Flexible seams allow more body conformity and movement.