Top panel: Ba II 4554 Å line profile in the observed spectrum (circles) of HE0336–2412 (CES0338–2402). Synthetic best-fit NLTE spectra, derived using pure r-process (dashed line) and pure s-process (dotted line) Ba isotope mixtures are almost indistinguishable, demonstrating that a reasonable fit can be achieved with any adopted isotope ratio. Vertical dashes show the relative contribution of different Ba isotopes to the r-process and s-process; see legend for designations. Bottom panel: Same as the top panel for HD 27928 (CES0422–3715).