ABSTRACT
When you join with tape the two pieces of film to be joined are laid end to end without an overlap. When a cement splice is made the two ends do overlap slightly. With the cement splicer the film is cut and emulsion is scraped off a small part of the edge of the end frame on one side of the join. Cement is applied to the clear film and the other piece of film to be joined is brought in contact with the cement-coated clear film before it has a chance to dry or harden. The second piece of film is not scraped clear of emulsion. If it were to be scraped clear the two pieces would allow light to pass straight through the film allowing a white flash to appear on the screen. The second piece of film is however cut to a slightly different length to allow a small part of the edge of the last frame to overlap the part of the other piece of film from which the emulsion has been scraped. The two pieces of film are therefore virtually welded together with film cement.
