Exposure and Development

1. Prepare the platemaker. Carefully inspect the glass on both sides and clean as necessary. (Any specks on the glass will be photographically exposed unto the plate.)
2. Place your plate on the rubber mat, beneath the glass, with the emulsion side up.
3. Position your transparency upside down, centered, on top of the plate . (i.e., backwards from how the image should look after printed.) In most cases, you will be placing the transparency onto the place in an “emulsion to emulsion” fashion. This assures the truest exposure.
4. Close and latch the glass frame.
5. Turn on the main power of the platemaker.
6. Press the vacuum switch. When the gauge stabilizes between 20 & 25 lbs., pull out the knob on the right side and flip the bed clockwise (180 degrees) to the upside down position by pushing the down the right corner. Make sure the bed locks with the knob holding it at the horizontal position.

7. Set the exposure counter to the desired count, then press the “T”. this will begin the exposure. Note the decimal counter – a setting of 15 will look like 15.0.
   • 15.0 is the standard exposure count for the platemaker, but some transparencies could require a different count. Thin/weak transparencies may need to be adjusted down, and fine halftones may need to be adjusted up. A step wedge test of 3.0 + 3.0 + 3.0 + 3.0 + 8.0 will show exposures at 8.0, 12.0, 16.0, 20.0, and 24.0.
   • Note: Photographic exposures are usually measured in units of time (e.g., seconds), and it is common to refer to the exposure counter as a timer. However, the UA platemaker is an exception and measures exposures in units of light (e.g., lumens). You will notice that the counter starts slowly, but increasingly speeds up as the light gets brighter.
8. When the exposure is finished and the counter returns to the original setting, pull out the knob and flip the bed back to the right-side-up position. Lock the bed in place.
9. Turn off the vacuum, open the glass frame, and remove the transparency.
• Rubylith (or amberlith) option: Cover image area with rubylith, and go through the steps to re-expose the plate through the rubylith. This burns out un-drawn margin areas and assures that they will not take unwanted ink.

10. Take the plate to the washout area and place it on top of the plexiglass support. (The plexi support should be relatively dry without any puddles.)
11. Pour developer onto the plate – enough that it can be flowed over the entire plate. Move the developer around with the developer pad to dissolve the emulsion from the exposed areas. If the developer depletes itself before all of the unwanted emulsion is dissolved, add more. The image is fully developed when all of the unwanted emulsion has been dissolved – be sure to get the edges clean.
12. When the image is fully developed, rinse the plate with water. All water and chemicals should go into the barrel, not into the sink.
13. Squeegee the plate and set it to the side propped upright.

14. Clean up:
    • Rinse and clean out the developer pad and remove access water with the squeegee.
    • Rinse the developing area and the plexiglass support, and squeegee water and chemicals into the barrel.
    • Turn off the main power to the platemaker, and return it to its original position.
    • Be sure to remove transparency and other materials from the platemaker.
15. The plate should be dry by now. Take it to a the slate platform on the “Bobby” press or to one of the glass slabs. Pour a small amount of plate finisher/cleaner/preserver onto the plate and spread it over the entire plate with a damp (not wet) sponge. Then buff it with a cheesecloth.
16. When the plate has dried, store it out of the light and enclosed in a light fast sleeve until you are ready to print.