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1952 Theatre Catalog, 10th Edition, Page 291 (255)

1952 Theatre Catalog, 10th Edition
1952 Theatre Catalog
1952 Theatre Catalog, 10th Edition, Page 291
Page 291

1952 Theatre Catalog, 10th Edition, Page 291

FIG. 1. An example cl nitrate film in an advanced stage of decomposition on an exchange reel.

in handling and storing nitrate film, the National Board of Fire Underwritersy regulations* should be consulted.

It is well known that nitrate motion picture film, even when stored in regulation vaults, will deteriorate upon aging and under certain conditions, spontaneous combustion may result. This deterioration is accelerated when the temperature and humidity are high and when films have been kept without inspection for some time. Also, once the deterioration has begun, it proceeds at an ever-increasing rate, until the decomposition is complete. This decomposition begins with a yellow discoloration, fading of the image, and undue brittleness. At later stages, the emulsion becomes sticky and decomposition may become so great that the convolutions of the film weld together in a frothing mass, having a disagreeable ordor. At the hnal stages the film may crumble to an acrid smelling brown pOWer. An example of film in an advanced stage of decomposition on an exchange reel is shown in Figure 1.

All nitrate films which are to be saved should be examined carefully throughout their length before being placed in the storage vault and re-examiiied at regular intervals. For tropical conditions of storage, the examination should be made every two or three months. In the theatre, it is advisable to check occasionally any specialized or promotional trailers

*itStundai'ds of the National Board of Fire Underwriters for Nitrocellulose Motion Picture Film as Recommended by the National Fire Protective Association," N.13.F.U. Pamphlet No. 40, July 1931) (Reprinted 1949). Copies may be obtained from National Board of Fire Underwriters, 85 John Street, Now York 7, New York.


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and other small film rolls which may have been on hand for some time.

The disposal of unstable or deteriorated nitrate films presents a problem. They should not be mixed with regular nitrate film scrap or thrown in rubbish containers. Such films should be kept under water in a suitable metal container until disposal can be arranged. Safe disposal should be arranged with the proper city or fire prevention authorities.

Identification System for Safety Film

Proper identification of nitrate and safety film, of course, is of paramount importance if accidents are to be prevented. The only safe practice is to assume that all 35mm motion picture film is nitrate unless demonstrated otherwise.

A safe, simple, foolproof method for identifying nitrate and safety film correctly is not as easy as it might seem. For many years film manufacturers have printed the words thITRATE FILM" at frequent intervals along the edge of film made on nitrate base, and the words NSAFETY FILM" along the edge of film made on safety base. This has usually been done by a latent image exposure at the time of slitting or perforating and the identification is visible only after processing. This identification system was adequate as long as only nitrate film was used for professional 35mm theatre productions. Now that both nitrate and safety films are in general use, there is the danger of misidentification caused by printing through from a safety negative onto a nitrate print or Vice versa.

Figure 2 illustrates what can happen when a nitrate positive is printed from a safety master and a safety duplicat 'ing negative. The nitrate print carries

not only its own identifying name in black but the words itSAFETY FILM" in white printed through from the safety duplicating negative, and the same in black printed through from the safety master positive. The original identify' ing name on a piece of film usually appears sharper than one resulting from a second generation print, but there is still a real danger of misidentification. Figure 3 is the reproduction of a portion of a print on safety film which was found in the trade. A sample had to be burned to establish the identity of the base.

It is thus apparent that the former system of nitrate and safety base identification is entirely inadequate. The Eastman Kodak Company has given a great deal of thought to this problem in recent years because of its importance in fire prevention. Many ideas have been suggested and it has finally been concluded

FIG. 2. A print on nitrate stock showing conflicting identifications printed through from a safety mas. fer positive and a safety duplicating negative.

FIG. 3. A portion of a print on safety film stock found in a film exchange. Note confusion of identifying names. The correct identity can be established by the presence of the safety frame-line mark. (See FIG. 43.)

1952 Theatre Catalog, 10th Edition, Page 291