Screen protector
A screen protector is an additional sheet of material—commonly polyurethane or laminated glass—that can be attached to the screen of an electronic device and protect it against physical damage. History. The first screen protector was designed and patented by Herbert Schlegel in 1968 for use on television screens. Screen protectors first entered the mobile-device market after the rise of personal digital assistants (PDAs). Since PDAs were often operated via a stylus, the tip of the stylus could scratch the sensitive LCD screen surface. Therefore, screen protectors provided sacrificial protection from this damage. Since then, the  ubiquity of mobile-devices have seen the screen protector become more widely used. Materials. Screen protectors are made of either plastics, such as polyethylene terephthalate (PET) or thermoplastic polyurethane (TPU), or of laminated tempered glass, similar to the device’s original screen they are meant to protect. Plastic screen protectors cost less than glass and are thinner (around thick, compared to for glass) and more flexible. At the same price, glass will resist scratches better than plastic, and feel more like the device's screen, though higher priced plastic protectors may be better than the cheapest tempered glass models, since  glass will shatter or crack with sufficient impact force. Screen protectors' surface can be glossy or matte. Glossy protectors retain the display's original clarity, while a matte ("anti-glare") surface facilitates readability in bright environments and mitigates stains such as finger prints. Disadvantages. Screen protectors have been known to interfere with the operation of some touchscreens. Also, an existing oleophobic coating of a touchscreen will be covered, although some tempered glass screen protectors come with their own oleophobic coating. On some devices, the thickness of screen protectors can affect the look and feel of the device. Screen protector A