Just a side note.

It looks like those who have finely calibrated their digital negatives for their process will have to recalibrate if switching to the fumed silica.

And a question...

Can one treat paper with the fumed silica and then put it aside for future use? The answer seems to be yes, chemically (it being so inert). But what about physically -- any danger of rubbing off the silica or otherwise damaging the surface in storage?