<p>This study investigates routes to increase depth of cure in vat photopolymerization of photoresins filled with photoabsorbing particles including carbides, ferrites, and activated carbon. A design of experiments was conducted by tuning variables across the particle, the resin, and the light package to determine the importance each variable in increasing the depth of cure. For highly filled systems, increasing the size and monodispersity of the particles, tuning the curing wavelength, optimizing the photoinitiator concentration, and tuning the resin additives and environment all can significantly increase the depth of cure. A suggested framework for on-boarding and optimizing filled resins is provided.</p> Graphical abstract <p></p>