Provided is 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.