There are many ways to classify the paper stocks, but generally speakingļ¼ most paper stocks used in the printing industry fall into two classifications: uncoated and coated stock.
Uncoated Stocks
Uncoated stock is paper that has no coated pigment applied to reduce the absorbency or increase the smoothness. The uncoated finishes can be described as vellum, antique, wove, or smooth.
Coated Stocks
A coated stock has a surface coating that has been applied to make the surface more receptive for the reproduction of text and images in order to achieve sharper detail and improved color density. By adding a coated clay pigment, the objective of coating the stock is to improve the smoothness and reduce the absorbency. Coated paper finishes can be categorized as matte, dull, cast, gloss, and high gloss. The coating can be on both sides of the stock (coated two sides, “C2S”) or on one side only (coated one side, “C1S”). Coatings added to groundwood papers give them a greater degree of permanency and the natural tendency for goundwood papers to yellow is reduced.