gum on vellum
Since no one is posting at all here's another one to muck up the e-waves:
One of my students, Keegan Fields, printed his final tricolor gum project on cheapy vellum. Yup. It was even registered. He said he shrunk it in really hot water for a really long time, and coated it with the paper resting on a bucket to deal with the curl. When I finally get a "student work" page on my website I will post them. They are quite beautiful with a light shining below. He did it because it was said you couldn't. He lived to tell the tale.