Place the laminated copper plate on the vacuumframe. Leave the top protective layer on.
Place the halftone or the bitmap on top.
Switch on the vacuum, place a lightproof sheet on top and turn on the UV light. For halftones: After 30 seconds’ exposure, move the lightproof sheet a little every 15 seconds producing a photopolymer film with an exposure scale going from 30 to 120 sec. The bitmap: After 5 minutes’ exposure, move the lightproof plate or foil a little every 1 minut and thus produce a photopolymer film with an exposure scale going from 5 to 15 minutes.
Take out the plate and remove the top layer by rubbing your hand across the edge of the plate. Place the exposed plate in the developer.
- Use a sponge in the developer as though you were washing the plate. Develop the plate one to three minutes with steady movement all over the plate.
- Take the plate out of the developer, rinse it in running water and check the dots with the back of your hand. They should feel like fine sandpaper in the coppery (black) areas of the image. If the development is weak, develop the plate further until you can see and feel the dots clearly.
- Rinse the plate and spray it with white vinegar from an atomizer and gently rub the vinegar into the plate.
Give the plate a final rinse in cold water, dab with newspaper and let it dry in the drying cabinet.