The present invention is directed to a process for retanning leather comprising the steps of: a) providing tanned or pre-tanned leather b) treating the tanned leather of step a) with a composition comprising hollow microspheres, preferably as an aqueous composition, the hollow microspheres have a true density of from 0.01 to 0.10 g/cm3 (25° C.) and/or a bulk density of the dry powder of 0.005 to 0.06 g/cm3 (25° C.), c) drying, whereby the temperature of the leather during drying does not exceed 75° C. as well as to leather obtained by said process.