retards the drainage and dewatering process which drastically slows down the papermaking process adding filler to the paper mat reduces the effectiveness of the strength additive because filler has a much higher specific surface area than fiber most of the strength additives added into the papermaking slurry go to filler surfaces and therefore there is less strength additive available to bind the cellulose fibers together this effect is more acute with pcc compared to gcc because pcc has a much higher surface area and is able to adsorb more strength additive one method of addressing this situation is by pre treating the filler material with a coagulant as described in u s application ser no 12 323 976 another method involves using preflocculation instead 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.