A method of preparing a stable dispersion of flocculated filler particles for use in papermaking processes comprises sequential addition of a first flocculating agent to an aqueous dispersion of filler particles followed by shearing of the dispersion, followed by addition of a second flocculating agent to the dispersion and further shearing of the resultant filler flocs to the desired particle size resulting in shear resistant filler flocs with a defined and controllable size distribution. In addition, a neutralizing coagulant can be added to the dispersion to partially or completely neutralize the charge of the filler before the first flocculating agent is added.