unwanted film damage that could be a defect or error - dust, hair, specks, emulsion scratches, splices, reel-change marks, a hiss, crackle or pop on the soundtrack, mottling of the image, scratches on the negative being printed positive, etc.; film preservation, restoration, and archival efforts help to keep older, decomposing, and endangered films from deteriorating and acquiring artifacts, through painstaking processes (oftendigital restoration)