I agree with Michael's consideration. Not just T-grain films but FP4+ and HP5+ also have hardened gelatine, resistant to higher processing/washing temperature. The number he gave, 72F is a safe one and it can be higher in this case. However, the numbers people give seem to lack clearly and reliably observable evidences (for example, small difference in a too small sample size) and they are just good rough guides, as many other things are. Going a bit more toward radical side, even the 20C/68F is not the definite standard. Eastman Kodak Company used to recommend 18C/65F for films and 21C/70F for prints. I even heared/read several times that they recommended 18C because this is the annual average temperature in Rochester, NY. Anyone knows the truth??(posted 8176 days ago)Just to clarify thing a bit, I like to note that the reason long wet time should be avoided with paper is different. Long wet time may lose some of the paper base brightness. Mechanical strength and stability of the emulsion and paper base can be sacrificed. (Even before these, you get more trouble in drying them flat)