Elastic Trim is ideal for adding stretch to a variety of garments. Elastic trim describes any trim that features a piece of rubber or elastane surrounded by woven fibers like cotton or polyester. Elastic can stretch up to twice its length. Although rubber might seem like a modern invention, it has been used by humans for thousands of years. Utilize elastic trim to create ruffles on the sleeves of a blouse, or a waistband on a circle skirt.