Abstract: A one-step process for simultaneously compressing and tempering fiberboard panel, which includes the step of applying to the panel prior to compression thereof an aqueous treating composition which comprises a polyvinyl acetate emulsion and optionally up to 40% of a hydrocarbon emulsion, up to 3% of a fluid, water-soluble organosilicone polymer, or up to 5% by weight of a starch crosslinking agent. The polyvinyl acetate emulsion is prepared in the presence of 6-10% by weight of a starch stabilizer selected from the group consisting of derivatized starches and/or converted starches and 0.5-1.5% of a surfactant. The preferred emulsions are polymerized in the presence of alkenyl succinate starches, most preferably octenyl succinate waxy maize starches.