Black Spline is a ribbed pvc used to hold insect screening in the frame. Without the tight fit, the screen will hang loose. The screen is rolled flat onto the frame and then held in place by the spline. This PVC ribbed spline allows the assembly to be easier than using a rigid plastic component for the screen. Black Spline slides into the channel to secure the screen panel. Even though the material is plastic, it is soft and resilient to provide a comfortable fit for the window & door components. Use a spline roller to easily install spline.
