Criteria for Plate Testing The listed exposure times are provided as a guide. The actual exposure times will vary according to the line voltage, tap setting, processing method and Gray Scale Step. All plates listed were exposed to the plate manufactur's recommended step, using a UGRA Control scale. Once the proper exposure was established, a final exposure was made using the UGRA and the FOGRA control scale. The final exposure was evaluated for proper exposure and best image reproduction. The plates were processed by hand using the the Plate manufactur's chemistry and their recommendations for hand processing. The glass to glass distance for the VT 4, 6 & 8 lighting systems were 39". Line voltage for the testing was 208 VAC. The transformer Taps were set for Tap #1 (200 Volts) AGFA Anitec Fuji IBF Kodak-Polychrome Precision Lithograining