What is Spandex Fabric?
Known for its extraordinary elasticity, spandex has been used extensively for foundation garments and all types of active sportswear [including swimwear] since its introduction in 1958. Spandex is frequently called by one of its trade names - Lycra®.
Spandex fabric can be stretched repeatedly and still snap back to its original shape and length. It can be stretched from four to seven times its length without breaking. When compared to rubber, it is stronger, more durable with greater tear resistance. It is more resistant to abrasion, flexing, sunlight, weather, heat, detergent, body oil, and perspiration. It is lighter weight and can be made into finer yarns. It can be stitched through without damaging the fiber and reducing the recovery.
Spandex can be added to any fabric, knit or woven, and to a variety of fibers to add stretch in the length, width, or both directions.
Today, it is used in small amounts to add stretch and freedom of movement, improve the look, feel, fit, and comfort; maintain the shape; and eliminate bagging. It is used in large amounts for high stretch designs such as foundation garments, women's swimwear, skiwear, swimsuits, dance apparel and skating costumes.
Sewing Swimwear Fabric
Layout/Cutting/Marking: Let fabric relax overnight. Before cutting, compare the amount of fabric stretch with the amount required for the design. Generally the greatest stretch goes around the body.
Stitching: Start each new project with a new needle in the smallest recommended size. Change needles frequently; synthetic fibers dull needles faster than natural fibers. To check the needle for burrs, stitch through a nylon stocking scrap. Use polyester thread, which is more elastic than cotton. Wind the bobbin slowly. When wound on high, the thread heats up and stretches. Then, when sewn into the seam, it relaxes, and the seam shortens or puckers. For more elastic seams, stitch with a narrow zig-zag (W,.5-L,1), and stretch slightly when stitching. Or stitch on a serger with a safety-stitch and textured thread on the loopers.
Seams: Use stretch seams where appropriate. When sewing women's swimwear, stabilize shoulder and waist seams and edges with stay tape or clear elastic.
Excerpted from Sew Any Fabric by Claire Shaeffer