Latex particles with high and low molecular weight (HM and LM) poly(methyl methacrylate) (PMMA) were used to prepare two sets of films with various latex contents separately. These films were annealed above the glass transition temperature. A UV-Visible (UVV) technique was used to measure the transmitted photon intensity, I-tr during film formation from latex particles. Transmitted photon intensity from HM and LM films increased as the annealing temperature increased. A void closure equation was derived for I-tr by using the Vogel-Fulcher viscosity equation. It is observed that as the latex film thickness, d, increased void closure constant. B, and viscosity increased in both HM and LM films. For a given thickness, d, the lower viscosity of particles in HM films results in better packing than in LM films.