Patented is a polymer composition with multistage polymer particles. Each of the particles includes a first polymer with: i) a polymerized unit of a multi-ethylenically unsaturated monomer and ii) at least one pendant absorbing group selected from the group consisting of phosphorus acid groups, phosphorus acid full-ester groups, polyacid sidechain groups and mixtures thereof. The first polymer has a glass transition temperature in the range of -60°C to 35°C and a second polymer with a glass transition temperature in the range of -60°C to 35°C. The second polymer is substantially free of at least one pendant absorbing group. The average weight ratio of the first polymer to the second polymer is in the 1:2 to 1:20 range.