The relative location of picture and sound in a motion picture print that produces proper synchronization during projection. In 16mm, answer and release prints are made with the soundtrack advanced 26 frames ahead of the picture. At 24fps, this distance represents over one second of footage. In 35mm, prints are made with the sound advanced 20 frames. Since each frame of picture must be held still while light shines through it, illuminating the screen, and since quality sound can only be read from film moving continuously past an optical or magnetic playback head, the picture frame and sound frame corresponding to the same event on film must be separated by a distance on film that will match the image projection with the sound reproduction. See editorial sync.