Alex, Standard commercial printing papers don't get soaked in the process,
and even if dampened are *coated* with an oily ink (in fact that may be
why coated -- so the ink doesn't soak in). My hunch would be that
a coated paper wouldn't be good for gum because clay would wash off during
soak. I wouldn't be surprised if it did likewise with other process, and I
wonder (tho maybe someone else can say for sure) if clay coated paper is
archival anyway .... Sounds like the price is right, tho -- why not try
something easy, like cyanotype.... Or even just soak the paper for a while
& see what happens.
Judy