I always read what has been posted by you two, and I didn't mean to gloss over it in my post. I do think, though, that it's the gelatin-to-gelatin transfer that should be considered the "fundamental" mechanism. To me it seems like the mordanting aspect is an improvement, not an embodiment of dye-imbibition itself, which can be demonstrated in the simplest form with a gelatin relief, dye and any absorbent surface.

So as far as Bill is concerned, the crux is whether PVA will act similarly to gelatin in its ability to absorb a dye solution, and that's what T-grain was addressing originally.