Thanks Ian, It's sort of funny, I got on to this persulfate thing and decided I would give it a whirl. The first neg was Tmax 100 and I used a little white tray on a light table so I could watch it. I watched and watched and watched, almost zero effect. I made another batch and tried an FP4 neg, ready to watch it too and it literally disappeared before I could snatch it from the tray!!! I had to think about that for a while before I went back to the well...EC