ZBrush as a Character Design Tool - ZBrush Creature Design: Creating Dynamic Concept Imagery for Film and Games - page 32

Visual Weight
Visual weight is a very important consideration. The relative size and placement of a shape can give it more
visual weight than others on the screen ( Figure 1-31 ). This can accentuate a design element for good or bad
effect. For example, the shapes of these horns in Figure 1-32 carry more visual weight the larger they get.
When the horns are smallest, as they are in image A, they serve no real purpose on the design; they add little
to the overall effect. In image B they carry a little visual weight but not enough to make the overall effect