https://www.TrexFencingFDS.com This contractor-contributed video shows how to create a clean line for your fence. In this video, the contractor explains how to use a string line to decide on the height of the Trex posts for a 6' tall fence. Transitioning a fence line to accommodate a slope is important to give the fence the look that flows evenly with the ground. Using a string line not only makes measuring for the placement of brackets, it helps to see how the top of your fence will look before you begin installation. For additional assistance, consult our website or call 877-700-8739.