Dot gain and TVI are sometimes used interchangeably. TVI stands for Tone Value Increase which is a more general measure of the difference in value between the value specified in the source file and the value of the printed piece. Instead of measuring an increase in dot size, it measures changes in tone. It is used when individual ink dots are not used in the printing process to produce the printed piece. A tone reproduction curve provides a relationship between tonal value increase and dot gain.