Additive manufacturing performed with solid particles can form microscopic structures based on the properties of the particles used. These microstructures will likely impact the performance of the product produced. Characterizing these microstructures is difficult since the interior of powders is a challenge to image. Most imaging techniques are limited to surface visualizations.We have established a methodology to directly visualize the resulting particle structure by mapping powder particle positions in the interior three-dimensionally. We use Confocal Laser Scanning Microscopy (CLSM) to capture stacks of cross-sectional images of micron-sized poly-dispersed electro-photographic printing particles. Assisted with image analysis tools, we have obtained the co-ordinates and deduced the radius for each particle in selected sampling volumes. With this information, we are able to recreate the particulate structure in three-dimensional space and to determine the microstructural parameters, such the packing fraction for this powder system.