American cinematographer. (1920)

Save The Surface And Save All Growing use of lacquer coating for both 16mm. and 35mm. films safeguards negatives and extends life of release prints. By FREDERICK FOSTER I ncreasing use of motion picture film outside of the large, well-equipped motion picture studios, such as in the 16mm. and television film industries, has brought with it a number of problems for producers arising from handling. Two factors which tend to impair screen quality are film abrasion and oil mottle. Abrasion or scratching is caused by care¬ less handling of the film when rewinding the original negative from one reel to another; when handling the negative during the break-down process; when viewing the negative in a Moviola or other type of film viewer; or improper handling when projecting, cleaning, re¬ winding, code numbering, etc. Today, film producers are demanding positive protective measures that will safeguard their original negatives against such damage. Oil mottle is another serious harmful effect which mainly concerns the posi¬ tive or release print. Usually oil mottle is the result of running a film through a projector which has been carelessly lu¬ bricated so that some of the excess oil is transferred to the film where it remains until it is removed by a suitable cleaning process. Too often oil on film is not con¬ sidered a dangerous condition and it often happens that oil that gets on a film during its initial screening remains there for the entire life of the film, greatly impairing its screen quality, of course. The modern treatment of film, both color and black-and-white, as a protec¬ tive measure against abrasion and oil mottle consists of coating both film sur¬ faces with lacquer. Lacquer coating affords many advan¬ tages which the practical minded film user cannot fail to ignore. Actually, no film surface will indefinitely resist abra¬ sion and scratches—even treated film sur¬ faces will become scratched. In this con¬ nection, however, lacquer coating pro¬ vides a primary advantage, in that nor¬ mal abrasions and scratches do not pene¬ trate the protective lacquer coating to damage the film surface. Since the scratched lacquer coating may easily be removed and the film re-lacquered, in¬ definite protection is assured the film sur¬ faces, and new print projection quality continues. This process can be repeated CORNER of Escar's motion picture lab¬ oratory, showing lacquer coating machine for 16mm. and 35mm. films. Controlled heat and filtered air quickly dries coated film. GLASS-ENCLOSED dustproof lacquer ap¬ plicator is shown at left. As film leaves supply reel, it travels over rotary appli¬ cator which deposits thin coat of lacquer on film surfaces. as long as the perforations are good, thus extending the useful life of the print. The advantages of lacquer coating negative footage and other original films, especially if quantity prints are to be made from them, is definitely obvious. In lacquer coating the producer has a film protection process equally effective for originals and production prints. Lacquer coating possesses additional virtues. For example, since it seals in the normal moisture content of the film, shrinkage and brittleness are reduced and the film remains pliable, thus mini¬ mizing breakage hazards in projection. This same sealing action of the lacquer coating tends to seal in the dyes in natural color film. Danger of first run damage to recently processed film is virtually eliminated by lacquer coating. This is accomplished by the lubricating effect of the lacquer, which prevents chatter or strain on the perforations from emulsion gathering on the aperture or pres¬ sure plates. It is evident that by lacquer coating both sides of the film, extra protection is achieved for films used in continuous projec¬ tors, and for any film likely to re¬ ceive extremely hard use by ex¬ tended running. The disturbing projection quality due to noticeable flicker caused by oil mottle on the film is probably considered a more serious problem than occasional abra¬ sions and scratches, which usually escape the observation of the average audience. In coping with this problem, lacquer coating makes another distinct contribu¬ tion to film protection and the require¬ ments of excellent projection quality. Screen flicker due to oil mottle on the film is, for all practical purposes, un¬ detectable with lacquered films. Since the glossy lacquer coating and oil spots on the film possess similar light trans¬ mission characteristics, the screen effect of oil mottle is practically eliminated. It is the difference in the transmission properties of uncoated film and oil spots that aggravates screen flicker. From the (Continued on Page 393) 382 American Cinematographer November, 1950