A phone screen protector is an accessory for cell phones, PDAs, tablet computers, and other devices that protects the screen. Primarily designed to protect touch screen devices without compromising image quality or device function, most phone screen protector accessories are self-adhesive sheets of very thin, high clarity, scratch resistant plastic. A typical phone screen protector of this type is made to be close to invisible when applied to the phone but to provide a high degree of protection. These protectors are disposable and leave behind no glue or other adhesive residue when removed. Other protectors are available for some devices that cover the entire device, not just the screen.
Most adhesive sheet phone screen protector accessories are made of some type of plastic. Urethane based screen protectors are the most common, but other types of plastic are possible. Several companies market such products, and most of them have sheets for almost any smart phone, tablet, digital camera, or other device with a touch screen or other digital display that could benefit from protection against scratches or other damage. Some companies even market adhesive sheet protectors for watches.
The rapid proliferation of smart phones and other touch screen devices in the first decade of the 21st century created a demand for these accessories. The urethane film technology was adapted from United States military applications, in which these tough films were first used for the protection of helicopter rotors. Later adapted for electronic devices used under difficult conditions of field operations, these thin film adhesive plastic protectors quickly found their way to the consumer market.
Further advancements have contributed to improvements in the basic phone screen protector. Advanced polymers and additives have led to the creation of thin film plastics that are said to be "self-healing". This type of adhesive protector can absorb scratches, and with the application of a little heat, such as from a hair dryer, the scratches can seem to almost dissolve as the plastic "heals" itself. Anti-glare features, polarization, and extended product life are just some of the improvements made to these products since their introduction.
Most products of this type require careful installation. Some require activating the adhesive by soaking in water or special solution before application, while others are simply "peel and stick". Each brand has its own specific methods and techniques for application, and so instructions must be carefully read and followed to ensure proper use and to avoid damage to the device.