Window film technology
Release Liner
The release liner is the temporary protective layer covering the adhesive side of a window film; the installer peels it off just before bonding the film to the glass.
Release liners are typically a thin silicone-coated polyester that protects the adhesive from contamination during shipping, cutting and handling.
During installation the liner is peeled away while the film is sprayed with the application solution, which both wets the adhesive and gives the installer a slip window to position the film accurately on the glass.
Liner handling is a quality marker — a well-trained installer never lets the liner touch a dusty surface or peel back on itself, both of which can transfer contaminants onto the adhesive.