Mixing profiles, D, during the evolution of the accretor. Left: evolution from X_c=0.7 to 0.0 in steps of 0.1. Right: profiles at selected evolutionary stages, before, during and after the RLOF. The shaded areas indicate the regions over which the mass varies, with the current mass indicated by dashed lines. The black lines, as denoted on the right-hand ordinates of the right panels show the corresponding profiles of hydrogen abundances.