Tears in the film
Major tears can rip film in half or into many pieces. All tears are repairable with patience, skill, and the right materials provided that no film is missing. However, whether a tear is worth repairing must be dependant on the value of the image and the quality of the resultant mend as all tears will show in the image to some extent.
Film patches
In some cases the film may be torn right across or into long linear shreds and involve many, sometimes even dozens of frames. The technician has to evaluate whether it is worth repairing the tear or not. It may mean saving several frames of the film that might be important to its continuity, but, on the other hand, the work is time consuming and, even if it is done well, there will always be an image of the tear that will be duplicated in the restored copy.
The first stage in a tear repair is to bring the torn edges together. The edges of tears are usually jagged, so the work of fitting them together is complex and delicate. It must be done very carefully, endeavouring not to leave any space between the edges that would shows a white line or space between the film pieces. These will be white if projected or black on the printed positive if the damaged film is a negative. Fundamental to all film repair work, however is the need to maintain the original film dimensions and the original perforation positions. In the past assembly film fragments had to done on a piece of clear blank film as a support, and cemented to that film to make a thick composite image.
Tape
Increasingly clear self adhesive tape is now used to align and support the fragments. Already perforated tape of the same gauge and perforation, similar to that used for tape splices, is used.
A common routine method is to use masking tape to fix the film to the worktable, and when the pieces are assembled and correctly positioned on the masking tape to apply the clear perforated tape over the top.
The damaged area is first cleaned with a soft cloth dampened with 1:1:1 trichloroethane so as to remove any grease marks that would impede the adhesion of the tape, as well as to remove any dirt. The procedure is then repeated to the other side of the film. There must not be any bubbles under the tape (they would be seen in the picture) and there must be a perfect overlapping of the perforations in the tape with those of the film, where they exist. This can be quite difficult in a film that has shrunk. If a length of perforated tape were to be applied over several frames of film, then the perforations in the tape would no longer correspond with those of the film and the perforations of the film would be covered. In order to avoid this, it is a good idea to proceed one frame at a time, covering each one with a piece of tape cut to a length of four perforations. In this way it is possible to guarantee a near perfect overlap of the perforations. All tape edges should be positioned between the frame lines.
Some printers are not very tolerant of the two extra layers of tape which creates a stiffer section of film than normal. This particularly true of modern rotary contact printers. The old repair system consisting of two layers of film base cemented together can only be printed satisfactorily using old style flat-bed printers.Increasingly clear self adhesive tape is now used to align and support the fragments. Already perforated tape of the same gauge and perforation, similar to that used for tape splices, is used.
A common routine method is to use masking tape to fix the film to the worktable, and when the pieces are assembled and correctly positioned on the masking tape to apply the clear perforated tape over the top.
The damaged area is first cleaned with a soft cloth dampened with 1:1:1 (explain) trichloroethane so as to remove any grease marks that would impede the adhesion of the tape, as well as to remove any dirt. The procedure is then repeated to the other side of the film. There must not be any bubbles under the tape (they would be seen in the picture) and there must be a perfect overlapping of the perforations in the tape with those of the film, where they exist. This can be quite difficult in a film that has shrunk. If a length of perforated tape were to be applied over several frames of film, then the perforations in the tape would no longer correspond with those of the film and the perforations of the film would be covered. In order to avoid this, it is a good idea to proceed one frame at a time, covering each one with a piece of tape cut to a length of four perforations. In this way it is possible to guarantee a near perfect overlap of the perforations. All tape edges should be positioned between the frame lines.
Some printers are not very tolerant of the two extra layers of tape which creates a stiffer section of film than normal. This particularly true of modern rotary contact printers. The old repair system consisting of two layers of film base cemented together can only be printed satisfactorily using old style flat-bed printers.