Coated vs. Uncoated Paper

Heavy ink coverage on uncoated paper can sometimes rub off or offset on the sheet next to it in a post-press stack. Various coatings, such as varnish, aqueous and ultraviolet, will seal the ink to prevent rub-off.

Dry time is another consideration.

"Coatings have a capillary action to them, so they absorb oils very fast from the ink," Kohler says. "Once the oils are removed, the resin particles are left available to oxygen and it dries. With uncoated paper, the smoother the sheet, the tighter the sheet is and the longer the ink-drying time."