..then stop and then developer again(!). Firstly, that'll teach me to not label my bottles - I ran some sheets last night through D76, stop and then Microphen, which I thought didn't smell quite like fixer but threw caution to the wind and used it anyway.
Secondly, I was a bit perplexed as to why the sheets continued to develop - not a lot, but a little - after they had been stopped? My stop bath is not that old so certainly shouldn't be exhausted. A shame, because having been suggested I shoot my Foma 100 at ISO80 rather than 100, they looked much less thin and when I put them in the "fix" they looked pretty good. Thankfully it was a few shots from the railway workshop so I can go capture them again. I guess that was a lesson.
Any clues?