Pre-soaking FB paper?
As developer carry-over into the fixer, and fixer residues in the finished print, are such problems, what is the reason that no-one pre-soaks FB paper in plain water before immersion in the developer. Would it significantly lessen developer activity in the emulsion? Or is diffusion of chemical into the paper base so fast that it wouldn't make any practical difference?
Pre soaking won't help prevent carry over, and yes it will lessen developer activity so you'd need to develop for longer to get similar results, so njo benefit.
You would gradually be diluting your developer and you would still have the carry-over to the other baths.
So why do some people presoak film?
Leaving out the anti-halation backing, why shouldn't you make sure paper is at the correct temperature before development if you do the same with film?
Originally Posted by noacronym
Where recommended, presoaking film is generally to help improve development uniformity, particularly with short development times, stand/semi-stand development, and when you can't get the film immersed in the developer quickly enough (for example, filling a multi-reel stainless tank through the daylight lid). Of course when tray shuffling sheet film, a pre-soak prevents the sheets don't stick together.
Some people recommend a film pre-soak in all cases. Some don't. Ilford says it is not required. I don't think Kodak indicates it is required either (for roll film).
These are not issues with paper development because 1) the paper is usually quickly immersed in the developer 2) paper development is virtually to completion (which would minimize or eliminate artefacts from uneven initial development), 3) agitation is generally continuous.
Regarding temperature, one could simply bring the tank to temperature by tempering it in a water bath. With paper, there is no tank, just the paper, which would likely come quickly to the developer temperature once immersed, without having a meaningful effect on the developer itself as long as there is sufficient developer volume.
Both Kodak and Ilford do not recommend that you presoak their films.
Originally Posted by cliveh
You don't tug on Superman's cape
You don't spit into the wind
You don't pull the mask off that old Lone Ranger
Some people are just contrarian by nature.
Paper simply doesn't matter as much. As long as you follow the same procedure and the developer temp stays the same you will tweak the exposure and contrast to get the image to look correct.
As long as you do things consistently between film runs it also doesn't matter if the film cools off the developer a bit. You would adjust your times to compensate. The key is consistency. I presoak in the Jobo but not in manual tanks because it brings the times between the two methods to almost the same.