Keson GB250 12-pack #18 Green Braided Nylon Mason Line, 250-ft, 155-lb Tensile Strength GB250 12-pack #18 Green Braided Nylon Mason Line, 250-ft, 155-lb Tensile Strength Because the twine is braided, it doesn't come apart even after multiple unwindings. It is perfect for large jobs and everyday use. 18-gauge line with an approximate tensile strength of 155 pounds.