Screens and meshes are commonly used to control what can go in and out of a window, and large screens and mesh nets can be used to protect an outdoor area from unwanted insects. Most American homes have screens made of plastic or metal wires on their windows, and for good reason. Mesh screen fabric can allow breezes, sunlight, and sound to pass through, but these screens and their flat spline sealant will prevent larger objects such as insects or birds from getting through. Flat spline, meanwhile, is the vinyl, ribbon-like material used to seal a screen into its frame,…