When sewn along the shoulder seam, a properly chosen tape acts as a stabilizing backbone. It stretches together with the fabric as the wearer moves, but then contracts back to its original length, stopping the seam from permanently stretching out.

Adding a stabilizing element that can stretch with the fabric but then recover to its original length is the key to keeping knitwear looking fresh and fitting properly over time. This is where elastic tape designed specifically for knits becomes indispensable.

When comparing TPU elastic tape to traditional alternatives, the advantages of modern TPU become clear. Traditional elastics are often made from latex or rubber wrapped in polyester or nylon fibers. While these can provide adequate stretch, they have several downsides: latex can cause allergic reactions in a significant portion of the population; the woven covering tends to fray over time; and the elastic may become stiff or brittle after repeated washing or exposure to heat.

Common problems that plague swimwear include deformation after repeated wear, loosening of leg openings and armholes, and elastic bands that twist, curl, or break down under exposure to pool chemicals. Many traditional elastics—such as those made from natural latex or rubber—are vulnerable to chlorine and saltwater, causing them to lose elasticity, become brittle, or even disintegrate over time.