Lithography-based Ceramic Manufacturing (LCM) is an Additive Manufacturing (AM) process based on the vat photopolymerization principle. LCM fabricates ceramic parts layer-wise by selective curing of the ceramic slurry. The main ingredients of the ceramic slurry are 1) Photo initiator, 2) Monomers, 3) Dispersants, and 4) Ceramic Particles. Photoinitiators are used to start the photopolymerization in monomers upon light irradiation. Then monomers are polymerized and act as a binder for ceramic particles. Ceramic powder loading in photocurable monomers/resin is a critical factor as it has a significant role in determining the slurry viscosity, the curing behavior of the slurry, green body strength, sintering shrinkage, etc. Higher powder loading makes the slurry viscous and poses difficulties in curing but is favored from the viewpoint of achieving defect-free parts. This work reports the development of alumina slurries up to 60 vol % of loading for the LCM process. The concentration of surfactant and dispersant was optimized along with the dispersion technique to maintain the required fluidity for higher solid loading. In addition, the processability of the developed slurry has been investigated with an LCM-based 3D printer.