In order to provide an economical process for applying a coating to at least one side, optionally to both sides, of a leather, in which gentle processing of the leather is ensured and hardening thereof is avoided, an aqueous plastic dispersion having compact particles containing a blowing agent being applied to this side or these sides and being allowed to solidify, and hollow microspheres being formed from the thermoplastic compact particles by supplying heat, the invention proposes that, after solidification, the plastic dispersion containing the compact particles is subjected to the action of expanded superheated steam at a temperature between 80° C. and 100° C. (FIG. 2).