The phenomenon in which parts of a printed image repeatedly appear in shadowy fashion on subsequent areas of the printed product that are printed with the corresponding color. This is an error which can occur with indirect printing processes such as offset printing. Ghosting is produced when screen dots have double or multiple contours and can occur in single-color printing, but more often in multi-color printing. Faulty printing of this type increases the screen tonal value and leads to dot gain. This slight shift in the position of the printing elements is caused by register fluctuations during printing, which may themselves be caused by the paper or the press.