Improvements in 3D printing allow for unique processes, finer details, better quality control, and a wider range of materials as printing hardware improves. With these improvements comes the need for greater computational power and control over 3D-printed objects. We introduce NVIDIA GVDB Voxels as an open source SDK for voxel-based 3D printing workflows. Traditional workflows are based on processing polygonal models and STL files for 3D printing. However, such models don't allow for continuous interior changes in color or density, for descriptions of heterogeneous materials, or for user-specified support lattices. Using the new NVIDIA GVDB Voxels SDK, we demonstrate practical examples of design workflows for complex 3D printed parts with high-quality ray-traced visualizations, direct data manipulation, and 3D printed output.