A window screen, insect screen or bug screen is a metal wire, fiberglass, or other synthetic fiber mesh, stretched in a frame of wood or metal, designed to cover the opening of an open window. Its primary purpose is to keep insects, leafs, debris, birds, and other animals from entering a building or a screened structure such as a porch, while permitting fresh air-flow.
The most common materials used for insect screening material are aluminum and fiberglass.
Aluminum is generally available in natural aluminum or in an applied charcoal color. The charcoal is much less visible and should be preferred where the view through the screens as well as the external appearance of the windows are important considerations.
Fiberglass is available in light gray as well as charcoal colors, the charcoal again offering better viewing and appearance.
Fiberglass is less expensive, and has the advantage of not “denting” when hit or pushed. However, the fiberglass mesh is somewhat more opaque than aluminum mesh, which darkens the external appearance of the window and reduces the amount of light transmitted from outside.
However, fiberglass screen degrades rapidly with exposure to UV light, leading to it fraying and breaking after just a few years, unlike aluminum which lasts permanently.