This was re-purposed from CEO Jim Raffel’s original on Feb. 7, 2006. You can read that post here.
In some facilities, print and color quality are measured and referred to as dot gain. Others refer to it as tone value increase or TVI. They refer to the same printing phenomenon: Dots of color appearing too close together in one area giving the printed version of the product a darker quality than what was intended. However, in our practices, we like to use the term TVI over dot gain.
Why we go with TVI
Fact 1: A densitometer (or spectrophotometer acting as a densitometer) does not actually measure dots.
Fact 2: Some systems being used for proofing result in continuous tone images with no dots.
Those on the SWOP committee that spearheaded the initiative to change this misleading term should be commended. When a 50% patch of a color increases to an apparent 65% patch of that color, the tone value has in fact increased regardless of whether that patch is made up of dots or not.
Along these same lines, we found this Graphics Arts Magazine article, which mentions the comparison of the terms dot gain and TVI. They relay that TVI is actually the better term for a simple reason: “not all modern printing technologies (for example, some inkjets or proofers) actually use dots.”