Dot gain is a measure of the difference between the actual ink dot size of the printed piece and the ink dot size specified by the source file. It refers to ink dots appearing larger on the printed piece due to either a mechanical or optical effect. Dot gain is not good or bad. It is simply a normal result of the printing process that must be taken into consideration during the creation of the source file, the choice of papers, printing process, inks, etc. If not taken into account, the result is a printed image that looks darker than intended.