A composition comprising an aqueous dispersion of multistage polymer particles comprising a first and a second phase, wherein: a) the first phase comprises, based on the weight of the first phase, from 25 to 60 weight percent structural units of a carboxylic acid monomer or a salt thereof, from 40 to 75 weight percent structural units of a nonionic ethylenically unsaturated monomer, and up to a total of 15 weight percent structural units of styrene and a high T g hydrophobic monomer; and wherein b) the second phase comprises a mixture of first and second polymers, wherein 1) the first polymer comprises, based on the weight of the first polymer, i) from 5 to 15 weight percent structural units of a carboxylic acid monomer or a salt thereof; ii) from 45 to 55 weight percent structural units of styrene; and iii) from 37 to 47 weight percent structural units of a combination of methyl methacrylate and the high T g hydrophobic monomer, comprising from 5 to 15 weight percent, based on the weight of the first polymer, of structural units of the high T g hydrophobic monomer; and 2) the second polymer comprises, based on the weight of the second polymer, i) from 80 to 99.9 weight percent structural units of styrene; and ii) from 0.1 to 0.5 weight percent structural units of a multiethylenically unsaturated monomer; wherein the weight-to-weight ratio of the first phase to the second phase is in the range of from 1:9 to 1:20; and wherein the weight-to-weight ratio of the first polymer of the second phase to the second polymer of the second phase is in the range of from 1:3 to 1:8; with the proviso that the first polymer and the first phase of the second polymer together comprise, based on the weight of the first polymer and the first phase of the second polymer, from 2 to 15 weight percent structural units of the high T g hydrophobic monomer, which is one or more monomers selected from the group consisting of cyclohexyl methacrylate, isobornyl methacrylate, 4- t -butyl methacrylate, t -butylstyrene, and n -butyl methacrylate. a) the first phase comprises, based on the weight of the first phase, from 25 to 60 weight percent structural units of a carboxylic acid monomer or a salt thereof, from 40 to 75 weight percent structural units of a nonionic ethylenically unsaturated monomer, and up to a total of 15 weight percent structural units of styrene and a high T g hydrophobic monomer; and wherein b) the second phase comprises a mixture of first and second polymers, wherein 1) the first polymer comprises, based on the weight of the first polymer, i) from 5 to 15 weight percent structural units of a carboxylic acid monomer or a salt thereof; ii) from 45 to 55 weight percent structural units of styrene; and iii) from 37 to 47 weight percent structural units of a combination of methyl methacrylate and the high T g hydrophobic monomer, comprising from 5 to 15 weight percent, based on the weight of the first polymer, of structural units of the high T g hydrophobic monomer; and 2) the second polymer comprises, based on the weight of the second polymer, i) from 80 to 99.9 weight percent structural units of styrene; and ii) from 0.1 to 0.5 weight percent structural units of a multiethylenically unsaturated monomer; 1) the first polymer comprises, based on the weight of the first polymer, i) from 5 to 15 weight percent structural units of a carboxylic acid monomer or a salt thereof; ii) from 45 to 55 weight percent structural units of styrene; and iii) from 37 to 47 weight percent structural units of a combination of methyl methacrylate and the high T g hydrophobic monomer, comprising from 5 to 15 weight percent, based on the weight of the first polymer, of structural units of the high T g hydrophobic monomer; and 2) the second polymer comprises, based on the weight of the second polymer, i) from 80 to 99.9 weight percent structural units of styrene; and ii) from 0.1 to 0.5 weight percent structural units of a multiethylenically unsaturated monomer;