Twisted nylon construction which produces a sturdy and durable line. Once the line is created it is wound onto the cardboard core. Line is then 'heat-set' to stabilize and further strengthen it. Not affected by mortar, oil or mildew. Will not absorb water, therefore reducing the likeliness of the line breaking. The fluorescent pink colouring provides high visibility, meaning the line can be used in a number of conditions. Perfect for staking out sites, concrete and landscape layout, as well as brick and block laying.