A professional who prepares photographic plates used to print pattern of aperture masks on sensitised steel. Responsibilities include:

• Examines unexposed plate to detect foreign particles or emulsion flaws.
• Transfers image from master plate to unexposed plate by means of contact exposure and immerses plate in series of chemical and water baths to develop image on plate.
• Examines plate over light box in darkroom to detect flaws and verify conformity of pattern with master plate.
• Measures dot size and centre distance, using calibrated microscope, and examines master and production plates for dot damage.
• Repairs defective plates by filling in missing dots, using photographic touch-up tool and ink.
• instals and aligns plates in printing case for display-screen fabricator.
• Prepares developing solutions, following formula.