These are white plates that are used
to create the final print plates. They come is sets that are packed in Brown paper.
Each pack contains all plates used for the complete comic story.
Each plate contains the art of four pages (usually 8 to 10 sub-sets per set. Each sub-set contains four different plate used in the four color process. One each: black, red, yellow, and blue. For example a story usually contains 32 to 40 plates. 10 different plates for each color. See examples in Photos below.