Robust method for producing latex seed particles

A method of producing resin seed particles comprising:

• (a) combining (i) water, (ii) an amount of a first branched alkyl diphenyl oxide disulfonate, (iii) a monomer, (iv) an optional branching agent and (v) an optional chain transfer agent in a vessel to form a monomer mixture;
• (b) combining (i) water and (ii) an amount of a second branched alkyl diphenyl oxide disulfonate in a reactor to form a seed surfactant solution, wherein the amount of the first branched alkyl diphenyl oxide disulfonate in the vessel of step (a) is at least four times greater than the amount of the second branched alkyl diphenyl oxide disulfonate in the reactor of step (b);
• (c) charging an aliquot of said monomer mixture into the reactor containing the seed surfactant solution;
• and
• (d) adding an initiator to said reactor containing the seed surfactant solution and the aliquot of the monomer mixture at an initiator adding rate to obtain resin seed particles,
• wherein the initiator adding rate varies by at least 350% during step (d), and further wherein the resin seed particles formed by step (d) are characterized by a D50 size and a deviation of the D50 size of no more than ±3 nm.