of a coagulant in at least one embodiment the filler content in the paper is increased by the following method an aqueous dispersion of filler materials is formed and the filler materials are preflocculated before being added to a paper fiber stock a first flocculating agent is added to the dispersion in an amount sufficient to mix uniformly in the dispersion without causing significant flocculation of the filler particles a second flocculating agent is then added following the first flocculating agent in an amount sufficient to initiate flocculation of the filler material in the presence of the first flocculating agent the second flocculating agent being of opposite charge to the first flocculating agent a paper mat is formed by combining the preflocculated filler material with the fiber stock and treating this combination with the strength additive the preflocculation of the filler material enhances the performance of the strength additive the fiber stock comprises fibers fillers and water in at least one embodiment the fibers are predominantly cellulose based in at least one embodiment the flocculated dispersion is sheared to obtain a particularly desired particle size while pre treating filler particles is known in the art prior art methods of pre treating filler particles.