Sunlight is a simple but realistic pattern that will make your pool like it s constantly glistening in the sun. Creating a constant movement will give your backyard pool area a relaxing and surreal feel. SmartLine® overlap swimming pool liners are designed to fold over the top of your pool wall and do not require a bead receiver. Overlap liners are held in place with coping. Be sure to check the measurements of your swimming pool to assure the correct size is purchased. Pool height is determined by measuring the outside wall from the ground to underneath the top rail.