Abstract: The frames of a film are scanned and exposure data, as well as masking data, are calculated for each frame from the resulting measurements. Following scanning, the frames are successively transported to a printing station. As a frame approaches the printing station, a mask is generated for the frame based on the respective masking data. The mask is produced by selectively roughening the surface of a transparent endless band or selectively applying a dye or pigment to the surface of the band. The band travels along an endless path which passes through the printing station, and movement of a mask and its corresponding frame are coordinated so that the frame is properly masked in the printing station. The masked frame is printed, and mask and frame are then withdrawn from the printing station while a succeeding frame and mask enter the printing station. If a dye or pigment is used for mask formation, the band can be conducted through a cleaning station where masks are removed after printing.