A method and apparatus for continuous contact printing from a moving master strip onto a moving duplicate strip of lightsensitive material. A vacuum is applied to the inner or facing surfaces of the master and duplicate strips to keep them in register with each other by withdrawing air from the space between them. Air is so withdrawn either in an entrance region before the longitudinally moving strips come into close proximity with each other, or in an exit region beyond which the moving strips begin to diverge from each other. At least some of the air that is withdrawn from the space between the strips is caused to leave that space along a path generally parallel to the direction of strip movement. The vacuum may be applied through a perforated wedge which guides the strips into close proximity with each other.