An aqueous glass fiber sizing composition that includes a polymeric film forming component, at least one silane coupling agent, and one or more lubricants is provided. The polymeric film forming component of the sizing composition includes a silanated polyvinyl acetate, an epoxidized polyvinyl acetate, and a modified epoxy emulsion. In preferred embodiments, the film formers are present in the sizing composition in ratios of 70:25:5, 50:25:25, or 63:18:18 of silanated polyvinyl acetate, epoxidized polyvinyl acetate, and modified epoxy emulsion respectively. Fibers sized with the sizing composition in a sheet molding compound process have improved wet-out characteristics.