Abstract: Disclosed is a process for producing an Al—Mn alloy sheet with improved liquid film migration resistance when used as core alloy in brazing sheet, including the steps of: casting an ingot having a composition comprising (in weight percent): 0.5<Mn?1.7, 0.06<Cu?1.5, Si?1.3, Mg?0.25, Ti<0.2, Zn?2.0, Fe?0.5, at least one element of the group of elements of 0.05<Zr?0.25 and 0.05<Cr?0.25; other elements <0.05 each and total <0.20, balance Al; homogenisation and preheat; hot rolling; cold rolling (including intermediate anneals whenever required), and wherein the homogenisation temperature is at least 450° C. for a duration of at least 1 hour followed by an air cooling at a rate of at least 20° C./h and wherein the pre-heat temperature is at least 400° C. for at least 0.5 hour.