In offset lithography, a press roller, typically installed as the first form roller, that has a special fibrous surface that either picks a hickey-causing particle from the plate, or surrounds the particle with ink to eliminate the characteristic white ring. Careful and frequent cleaning of this roller is important in order for it to maintain its usefulness. The position of the roller in the roller train also has effects on its efficiency, and its ability to cause other problems. Installing it as the last form roller contacting the plate can cause mottle or graininess, and if the first form roller is a combination ink/dampening roller, the hickey-picking roller should be placed second. The closer the roller is to the plate, however, the less coarse its surface fibers should be to avoid transferring the texture of the roller to the plate.
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