Systems and films for protecting surfaces of various substrates, including electronic devices, such as portable electronic devices, include a liner with a strip liner and a main liner. The strip liner, which covers a small strip of adhesive on the back side of a protective film, is configured to be removed before the main liner. With the small strip of adhesive exposed, the protective film may be aligned with a substrate and, if necessary, removed from the substrates and repositioned thereon. Thereafter, the main liner may be removed to enable complete application of the protective film to the substrate. Methods for securing protective films to substrates are also disclosed.