A method of papermaking comprising filler, the method comprising the steps of: providing a blend of filler particles, at least one drainage additive or wet web strength additive or wet strength aid selected from the list of: glyoxylated Acrylamide/DADMAC copolymer, poly-vinylamine, poly-vinylamide, poly-diallylamine, and any combination thereof, and cellulose fiber stock, treating the filler particles with a composition of matter in the absence of cellulose fiber stock, the composition of matter being a coagulant, wherein at least some of the composition of matter is added to the filler with a rotating admixing apparatus, the apparatus having a distribution head, which is rotated by a drive with a rotational speed of 1,000 to 2,500 revolution/min, is arranged in a container containing a slurry of the filler particles, and is associated with a rotational plane, and the distribution head has, along a circumference thereof, which surrounds a rotational axis, distributed outlets from which the composition is passed into the slurry and mixing blades, wherein the outlets are formed as openings and the mixing blades are formed as strips extending transverse to the rotational plane and having a length equal at least half of an inner diameter of the slurry pipe; and delivering the composition to the distribution head for admixing the composition to the filler slurry; combining the filler particles with the cellulose fiber stock, treating the combination with the at least one wet strength aid or wet web strength additive or drainage additive, and forming a paper mat by removing some of the water from the combination, wherein at least 10% of the filler particles are precipitated calcium carbonate and at least 10% of the filler particles are ground calcium carbonate, the cellulose fiber stock comprises a plurality of cellulose fibers and water, and the composition of matter enhances the performance of the wet strength aid or wet web strength additive or drainage additive in the paper mat. providing a blend of filler particles, at least one drainage additive or wet web strength additive or wet strength aid selected from the list of: glyoxylated Acrylamide/DADMAC copolymer, poly-vinylamine, poly-vinylamide, poly-diallylamine, and any combination thereof, and cellulose fiber stock, treating the filler particles with a composition of matter in the absence of cellulose fiber stock, the composition of matter being a coagulant, wherein at least some of the composition of matter is added to the filler with a rotating admixing apparatus, the apparatus having a distribution head, which is rotated by a drive with a rotational speed of 1,000 to 2,500 revolution/min, is arranged in a container containing a slurry of the filler particles, and is associated with a rotational plane, and the distribution head has, along a circumference thereof, which surrounds a rotational axis, distributed outlets from which the composition is passed into the slurry and mixing blades, wherein the outlets are formed as openings and the mixing blades are formed as strips extending transverse to the rotational plane and having a length equal at least half of an inner diameter of the slurry pipe; and delivering the composition to the distribution head for admixing the composition to the filler slurry; wherein at least some of the composition of matter is added to the filler with a rotating admixing apparatus, the apparatus having a distribution head, which is rotated by a drive with a rotational speed of 1,000 to 2,500 revolution/min, is arranged in a container containing a slurry of the filler particles, and is associated with a rotational plane, and the distribution head has, along a circumference thereof, which surrounds a rotational axis, distributed outlets from which the composition is passed into the slurry and mixing blades, wherein the outlets are formed as openings and the mixing blades are formed as strips extending transverse to the rotational plane and having a length equal at least half of an inner diameter of the slurry pipe; and delivering the composition to the distribution head for admixing the composition to the filler slurry; combining the filler particles with the cellulose fiber stock, treating the combination with the at least one wet strength aid or wet web strength additive or drainage additive, and forming a paper mat by removing some of the water from the combination, wherein at least 10% of the filler particles are precipitated calcium carbonate and at least 10% of the filler particles are ground calcium carbonate, the cellulose fiber stock comprises a plurality of cellulose fibers and water, and the composition of matter enhances the performance of the wet strength aid or wet web strength additive or drainage additive in the paper mat.