Well, Mason's book contains equations that are applicable to both film and paper both. They relate to the concentration of hypo+silver complexes with respect to time of wash in still and running water.

So, from that sense, you cannot differentiate in the equation between film or paper as it is independant of medium. It depends on rate of change. Thick film or paper washes more slowly than thin film or RC. I have published this entire portion of his work in simplified terms twice on APUG. It usually confounds people, but the bottom line is that the concentration of material in the photo material must change. If you use standing water or no agitation or both, then an equillibrium is reached and concentration is no longer changing. It becomes static or stagnant! You must agitate with running water to get the best wash. It is done when the material tests free of Silver and free of Hypo with appropriate test kits. This will vary depending on your water supply.

On another tack though, Haist reminds us that Metol washes out in an acid fix but HQ does not and in subsequent washes, Metol + acid fix is faster washing out in water but HQ + alkaline fix is faster washing in water. This is an interesting quandary.

The Dimezone/Phenidone family are more or less neutral wrt fix.

So, Haist suggests using something to swell gelatin (pH in this case) to speed washing and this is how TF-4 works. I'll have more to say on that in a few weeks perhaps, because there are other ways to swell emulsions and speed washes.

PE