When I was a teen, I visited Ed Hutchin’s studio. He makes amazing editioned books.http://www.artistbooks.com
He introduced me to gocco printing, tunnel books and flexograms. He has a great, simple how to on how to make a 4 sided, 1 page flexogram.
http://www.artistbooks.com/flexagons/flexmake.html I love making these with kids. They are magical!