All established fixer formulas of this and the last century fix film/paper to archival standards, or they wouldn't have been "established".
This is exactly what I thought, but couldn't express so well.
I'll be sticking with an Ammonium Thiosulphate and Sodium Sulfite formula, just like PE recommended above. Should be good and fast enough, and work for both film and paper, including my beloved T-Max 400.
Thanks again, Rudi.
