Pulp Diction

"The surface smoothness of a paper plays a critical role in toner adhesion—the smoother the surface, the better the adhesion," Hieronymus says.

Paper smoothness is measured in Sheffield units, with lower numbers representing smoother surfaces. Sheffield units for high-quality digital printing paper, Hieronymus says, usually range between 50 and 75; by comparison, offset papers generally range between 100 to 200 Sheffield units.