A latex which forms a film by evaporation at a temperature of less than 40° C. is based on hydrophobic polymer particles having a core/shell structure. The particles consist of 70 to 90% by weight of at least one polymer with a soft character having a glass transition temperature of less than 20° C. forming the core, and 10 to 30% by weight of at least one polymer with a hard character having a glass transition temperature of greater than 50° C. forming the shell. When applied to any surface and after drying at low temperature, the latex, without the use of any coalescents or volatile organic compounds, provides a continuous film which is homogeneous, has no surface tack and has good mechanical integrity.