Abstract: A stable aqueous dispersion is prepared by emulsifying an immiscible mixture consisting essentially of molten rosin, alkali metal alkyl benzene sulfonate and water, said immiscible mixture having a temperature in the range of from about 165.degree. C. to about 190.degree. C., and cooling said emulsion. The product consists of a substantially stable aqueous dispersion consisting essentially of water, rosin material and alkali metal benzene sulfonate in an amount sufficient to stabilize the rosin material. Sized cellulosic substrates are prepared by mixing with an aqueous slurry of cellulosic papermaking fibers a sufficient amount of the aqueous dispersion described above to size the cellulosic paper fibers, forming the fibers into a web, and drying the web.