Quote Originally Posted by polyglot View Post
I absolutely do not want to discourage you from this work, because access to a liquid-concentrate long-life XTOL would be fantastic even if it's just a recipe. But I should point out that Xtol-equivalent developers are available from Freestyle under generic brands, though I've not tried them. Personally, I just bought 15 bags of the yellow and I expect they'll last me a decade.
That's a good point about XTOL-clones already being available. I wonder how much testing they've been through?
Anyway, you might want to store those 15 bags in the freezer. I don't know what their shelf-life at room-temperature is, but it's probably under a decade.
Testing is an interesting topic. I've been thinking of the kinds of tests I'll want to run my concentrate through. These include:

  • Aging in various storage-conditions (hot humid areas are probably the worst).
  • Tolerance to errors in measurements by users.
  • Water types: hard, soft, well, softened.
  • Film types: PanF on the slow side, to Delta 1000/P3200.
  • Temperatures: 18C to 28C should cover the range.
  • Pulling and especially pushing.
  • Dilutions, although this dev is more dilute than most so we might not want to dilute it any more.

Each test would need to be a full roll to check capacity, and compare grain/density/sharpness with XTOL.
Any other tests that should be done?

Mark Overton