What material is often used to cover windows for security?

The best option for covering windows for security is typically glass, especially when talking about reinforced or specialized security glass. This type of glass, such as laminated or tempered glass, is designed to withstand impacts, making it much harder to break than standard glass. Security glass can deter break-ins by resisting shattering and can also be combined with additional security mechanisms like window frames, locks, and an alarm system for enhanced safety.

While the other materials listed may have their uses in security contexts, they are not usually employed in the same way to cover windows. Steel, for example, can be used in the form of security screens or shutters, but when discussing direct window coverings, glass is more common. Plastic could be lightweight and impact-resistant, but it does not provide the same level of security as reinforced glass. Wood can be used for window coverings as well, such as in boarding up windows, but it lacks the shatter-resistant qualities of purpose-built security glass. Thus, glass is the most prevalent and effective choice for securing windows.