A process is disclosed for making paper having improved filler retention and opacity. The process includes the step of adding Additive A and Additive B to a slurry in a wet end of a paper machine wherein the slurry comprises pulp and a filler. Additive A is a wet strength agent. Additive B is an anionic polymer having a charge density from about −3000 to about −7000 ueq/g on a dry basis when measured in a buffer having a pH of about 6. Additive B also has a weight average molecular weight of from about 150,000 to about 1,000,000, Daltons.