(57) A composition for flocculating paper- or boardmaking filler comprises particles of starch, in aqueous suspension, and a flocculating agent, eg. a polyacrylamide. Preflocculated filler for addition to a paper- or boardmaking stock may be prepared by adding such a composition to an aqueous slurry of filler particles, eg. calcium carbonate. The use of particulate starch that is insoluble in water at temperatures normally encountered in the wet-end of a paper- or boardmaking process, in particular temperatures below 35°C, obviates the need for a preliminary solubilisation step. However, the starch is soluble at temperatures encountered in the drying stage of the paper- or boardmaking process, where a starch solution is formed which is distributed through the paper matrix and imparts thereto additional strength.