Chris,
You may also try an acrilic coating or fixative such as manufactured by
Grumbacher (sic?). It comes in gloss and mat. The gloss will require
several coatings on non-smoth paper and may not ever give a gloss on
rough papers. The material is claimed to be archival and removable.
I have used the fixative on Pt/Pd prints on paper that will be displayed
without a cover glass (as in my folding screens). I use the fixative to
help prevent accidental scratching of the Pt/Pd prints. (Pt/Pd prints
on paper are easily scratched, although on fabric they seem to be
scratch-proof.) I have noticed that the fixative coating results in a
little more detail and depth in the shadow areas, not quite what being
under water gives but in that direction.
Give it a try. (Note: Apply the fixative in a well ventalated area and
do not breath the fumes as they are dangerous.)
Jeff