To a certain extent, the degree to which a mill produces a clean sheet also depends on its coating formulations. Coatings with strong binders reduce the amount of debris. But that's not possible if the sheet is warping, has welts, or shrinks. A sheet can loose its dimensional stability due to improper fiber furnish, incorrect drying, inconsistent moisture, or any combination of these. Good fiber furnish is a matter of balance between long and short fibers.
Long fibers create a stable, yet rough sheet.
Short fibers create a much smoother surface, but do not add much strength. Printers should consider a C1S stock that combines a mix of both fibers. When the right balance is achieved, the resulting sheet is durable, smooth and stable. Non-uniform moisture can also reduce dimensional stability. This is often caused by insufficient control over a mill's internal processes.