It refers to a phenomenon that the moisture content exceeds 14% when the board is off the machine for 30~60s.

dark spot

Also called dead spots.

1) Refers to imperfections on the paper after the paper is finished.

2) The surface of the high-gloss textured paper exhibits a partially low-gloss part.

Rough fiber bundle

Bonded together fiber sheets without dissociation. That is, the flaws caused by the incompletely scattered fibers on the paper surface.