Component addition polymerization

1. A collection of polymeric beads, wherein the beads comprise

(i) 75 to 99% by weight, based on the weight of the bead, polymerized units of monofunctional vinyl monomer, and

(ii) 1 to 25% by weight, based on the weight of the bead, polymerized units of multifunctional vinyl monomer;

wherein, within each bead, the average concentration of moles of polymerized units of multifunctional vinyl monomer per cubic micrometer is MVAV;

wherein, within each bead, T1000 is a sequence of 1,000 unique connected polymerized monomer units;

wherein, within each T1000, MVSEQ is the weight percent polymerized units of multifunctional vinyl monomer, based on the weight of T1000;

wherein MVRATIO=MVSEQ/MVAV;

and

wherein 90% or more of the beads by volume are uniform beads, wherein a uniform bead is a bead in which 90% or more of all T1000 sequences has MVRATIO of 1.5 or less.

2. The collection of polymeric beads of claim 1 , wherein, in 90% or more of the beads by volume, 90% or more of all T1000 sequences has MVRATIO of 1.25 or less.

3. The collection of polymeric beads of claim 1 , wherein the monofunctional monomer comprises styrene.

4. The collection of polymeric beads of claim 1 , wherein the multifunctional monomer comprises divinylbenzene.

5. The collection of polymeric beads of claim 1 , wherein 35% or less of the T1000 sequences have MVRATIO of 0.5 or less.