International projectionist (Jan-Dec 1951)

NITRATE FILM SAFETY FIG. 3. The new Eastman visible frame-line ma wise frame-line mark after every fourth perforation printed along the extreme edge of the film. Eastman 35-mm black-and-white Safety Motion Picture Positive Film now carries a lengthwise frame-line mark after every fourth perforation located exactly between the perforations instead of at the extreme edge of the film. This is the only area on the film which is ordinarily not exposed in printing. This new safety frame-line mark when used on safety negative film will not print through on positive film, provided that care is taken to see that printers never expose the area exactly between successive perforations. A more positive identification is thus obtained — whenever the new safety frame-line mark is found, one can be reasonably certain that the film is on safety base regardless of nitrate framelines or nitrate edge printing which may have been printed through from the negative. If the safety frame-line printing is not present, the film is either on nitrate base or on safety base made prior to the use of the new frame-line. Black Ink Now Used Both the nitrate and safety types of visible frame-line printing are applied to the back of the film by means of black ink instead of by latent image exposure and, therefore, are visible on the raw film (Fig. 3) as well as on the developed film (Fig. 4) . The ink used will withstand processing solutions and normal handling wear. Even if the film is flashed before development, the ink is visible by reflected light, although not by transmitted light. The new safety frame-line mark has FILM rk on safety raw stock compared with nitrate. been used on 35-mm black-and-white Eastman Safety Motion Picture Positive Film since early in 1949. It will appear on all 35-mm Eastman safety motion picture films (both negative and positive types in black-and-white) as soon as the necessary equipment changes can be made — it is hoped, sometime during 1951. (All color films manufactured by Eastman Kodak Company are made on safety base but may not carry this new frameline mark.) Of course, some Eastman safety film is already in circulation which does not have this new safety frame-line printing, but as time passes, this method of identification should prove of increasing value.* Attention is drawn to the fact that nitrate film formerly manufactured by Canadian Kodak carried a visible frameline mark running lengthwise of the film instead of widthwise. as in the case of Eastman nitrate film manufactured in the United States (Fig. 5). The Canadian Kodak nitrate frame-line mark was located at the extreme edge of the film. It may therefore be distinguished from the new Eastman safety frame-line mark located between the perforations. Thus both the direction and the location of the frame-line mark must be checked to establish the identification of the base. A Fluorescent Edge For Safety Film The new visible frame-line printing described above as a useful and necessary method for identifying safety film, but it also has its limitations. In a spliced roll, every separate strip would have to be examined to make sure that the entire roll including leader and trailer was safety film. Correct identification of the whole roll is especially important for sorting films going into storage vaults where a small piece of nitrate film might damage other films. It is also important in sorting film for scrap recovery. In such cases, individual examination of every spliced strip would be very laborious and costly. It was felt that some rapid method of determining whether or not a roll of film is all safety is necessary. The method which has been adopted *A distinctive type of frame-line mark for safety base motion picture materials manufactured in foreign countries is also being instituted. L_ NITRATCj f>Lm» _SA.r_CTY_tli.li_ FIG. 4. The new Eastman visible frame-line mark on processed safety film compared with nitrate. INTERNATIONAL PROJECTIONIST • March 1951 15