Printing is widely affected by dot gain, this is shown when prints come out darker than expected. This is the result of halftone dots increasing in diameter during the prepress. This happens while preparing media and machine’s optical and physical properties for the printing process.
Mechanical and optical are the two main types of dot gain. Mechanical dot gain is caused by the presses and their own set of quirks whereas optical dot gain is affected by the printing method, paper used and inks. Paper plays a big role in these printing methods as different papers absorb and hold ink differently directly affecting the amount of dot gain.
Dot gain can cause multiple defects in one’s printing. It affects its quality as loss of detail can occur in halftones and separations. It causes screen tints to print too dark and colours might not match with the swatch book.
Dot gain can be an issue to nearly all print processes, though the causes differ.