> What quality does the starch/dextrin of the
>original formula have or lack (other than potential mouse food)?
I infer from Judy's comments that she questions the need for starch at all. If
so, I quite agree.
In my experience oil prints work perfectly well with a small addition of alum to
the first 5 % coat of gelatine followed by two coats of 7 % gelatine. The base
paper is Bockingford. The gelatine, deionised ossein.
The starch and the silica seem to be unnecessary complications. If, however,
additional tooth is required for gelatine sized shiny surfaces such as glazed
tiles, pumice powder from art shops is sold for just that purpose.
TerryKing