What factors affect mechanical dot gain?

The paper that is used, the ink, the ink color, the printing press, the roller pressure, and the press speed all can affect dot gain. Uncoated papers like newsprint have a higher dot gain than coated papers. For color printing, the dot gain will vary between colors. The dot gain for cyan, magenta, yellow and black will not be the same. Therefore, the dot gain for each color of ink used in the printed piece must be measured to accurately portray the dot gain for the piece. Web presses normally produce a higher dot gain than sheetfed presses.