Using the dipcoating technique, we fabricate erbia-coated quartz fibers and glass slides. Further we present a thin film model of the dipcoating technique applied to the glass slides. The model includes evaporation of the solvent and a bulk reaction term to simulate the creation of the erbium oxide that forms the coating. Evolution equations for the solvent and coating thicknesses are developed and solved numerically. We study how the solvent evaporation rate, the bulk reaction rate, the dynamic viscosity, the angle of the inclined substrate, the characteristic depth of the solution thickness, the initial profile of the solution thickness, and the length of substrate affect the coating thickness. The model is calibrated using the experimental results to provide a tool for predicting the coating thickness.