At the 4-component level of theory, the EPR g-tensor is a first-order property, i.e. each component of the g-tensor is an expectation value. This makes visualization of the g-tensor in terms of 3-dimensional real-space functions straightforward. These functions can be considered as 'g-value densities', and be plotted to give a 3-dimensional visualization of the g-tensor. This can be decomposed further into terms corresponding to different operators in the g-tensor calculation. Initial results of the visualization of the g-value density are presented, including of changes caused by H-bonding. This new approach expands existing techniques for analysis of factors affecting the g-tensor. (C) 2015 Elsevier B.V. All rights reserved.