Line is usually made from a brightly colored, high-visibility material, such as nylon or polyester, making it easier for the bricklayer to see the line and maintain alignment., Line is designed to be durable and withstand the rigors of construction work. It is often resistant to abrasion, stretching, and weather conditions., Line has a high tensile strength to withstand the tension applied while tightening and maintaining tension between the line anchors.