A printing defect in which successive passes of a printed sheet through a press do not print an image in the spot they were intended to, typically a problem in multi-color printing. Misregister typically occurs due to changes in a paper's dimensions, either from moisture gain or loss, or from mechanical stretching. An overabundance of fountain solution can contribute to the dimensional changes of paper that contribute to misregister. (See Dimensional Stability and Moisture Content.) Misregister is commonly caused on web presses by poor side-to-side alignment of web with the printing unit or variations in web tension. See Register.