Automotive tinting specifics
Fingerprint Haze
Fingerprint haze is the cloudy effect that appears if film is touched on its adhesive side before installation or contaminated by skin oils during the install.
The adhesive side of window film is highly receptive to contamination. A bare-handed touch leaves skin oils that prevent the film from bonding cleanly to the glass, producing a hazy spot.
Professional installers wear powder-free nitrile gloves and handle the film by the edges. They also wet the adhesive side with application solution before touching it with anything other than gloved hands.
Fingerprint haze is rare on premium installations and very common on cheap ones. It is one of the visible signs that a workshop is rushing or under-trained.