Paper Clay is so much fun.
In my experience, once you open a package of Paper Clay, you should use it all up quickly, as it either dries out, or if you keep it in a plastic bag, it can mildew.
Grab some ceramic tiles, and put small globs of clay on them, smoosh them down and stamp into them.
After the clay is completely dry, seal it with a spray or paint on varnish, then antique it with a watered down acrylic paint. Wipe off excess paint with a paper towel.
Make lots of these to add to your element collection