You're right formica does do the curlies if not mounted down to something. I
guess you could glue two pieces back to back with the standard rubber glue
used to put it on countertops. I shy away from aluminum as it might cause
problems with developing platinum/pd. I know you can't develop pt/pd in a
stainless tray so aluminum might be a problem there. You just might want to
do gum/pt sometime! There's a window glass replacment material found in
hardware stores, it looks promising as a substrrate material.
I first used Seal 4000 Drymount tissue as it is supposed to be low temp and
does not have a paper core, it's just a sheet of the glue. Later I used the
Colormount stuff -- low temp as well. I've used the old standard stuff as
well. They all peel off with no trouble, though you may need to do it in two
steps. Get it good and hot and it'll zip right off. Make sure not to get
even the smallest spot of the glue on the face of the print, it'll never
take pigment and be forever a white spot on the print.
Once the print is stripped off it has a gluey back and usually has a hard
curl so it doesn't act much like paper anymore. I think you are more or less
committed to trimming and remounting it. I think I mentioned that I used to
remount it on a piece of the same paper and then overmatt that.
BTW I've never een any printed confirmation of anyone substrating in the
Classical Era. Knowing how clever those folks were, it only seems logical
that someone would have tried it. Alas, the first confirmation of my
suspicion mentioned in the original message.
-- Dick Sullivan
Bostick & Sullivan