The Visual Checkerboard section is built of individual pixel elements. The Visual Checkerboard section lets you visually assess plate processing and exposure. It also lets you quickly compare two similar plates.
The upper half of the Visual Checkerboard contains 1x1, 2x2, 3x3, and 4x4 pixel blocks. The lower half contains more coarse 10x10 pixel blocks.
Each area attempts a geometrically exact 50% tint made with different pixel patterns. Use the 10x10 pixel block as the reference to compare with the finer pixel elements on the upper row. In theory, each checkerboard dot pattern should appear as a 50% tint. In practice, however, the checkerboards may not have the same appearance.
The 1x1 pixel checkerboard is the most sensitive indicator of variations in imaging conditions. Slight differences in exposure, temperature, or processing can produce a noticeable change in appearance compared to the reference 10x10 pixel block. As a result, the appearance of the 1x1 pixel checkerboard cannot be used to evaluate acceptable image quality.
Each successively larger pixel grouping should come closer to a true 50% tint. The 10x10 pixel checkerboard (similar to a 50% halftone 170 lpi screen) is typically within 1%.
As a quick assessment, visually compare the 1x1 and 2x2 checkerboard densities against the 10x10 checkerboard. For negative plates, for example, the plate should be acceptable when the 1x1 block appears to be slightly lighter than the 10x10 checkerboard, and the 2x2 block is barely distinguishable from the 10x10 checkerboard.
See the Application Notes for specific recommendations for your platesetter and plate system.