A pickout or plucking hole is a paper defect that happens in the paper making process. It is similar to a slime or water drop hole, therefore identifying it requires another approach.
There are several causes of holes forming in a paper machine.
1. Equipment defects.2. Bacterial slime in the pulp.3. Sticky material on the rollers
The third reason is the cause of a pick-out or plucking hole. As the roller rotates, dust or a buildup of paper fiber sticks to the web of roller and causes a continuous hole at regular intervals.
Below is a close up of a roller inside a paper machine. If any dusty or fibers collect on a spot in the roller, it will cause a puncture in the paper at regular intervals.
How to identify this defect
The only way to identify this paper defect is by finding it at regular intervals in the stack of sheets or paper roll. The diameter of the roll in the paper machine will determine the distance between the holes. Some rollers are quite large and may have long intervals.
If a pattern is discovered, you will need the distance measurement when making a claim against the paper manufacturer for lost time and waste on your offset printing press.
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